From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 1 Jun 2015 19:45:19 +0000 (-0700)
Subject: Merge branch 'fm/fetch-raw-sha1'
X-Git-Tag: v2.5.0-rc0~59
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/a9d34933?hp=68ee628932c2196742b77d2961c5e16360734a62

Merge branch 'fm/fetch-raw-sha1'

"git upload-pack" that serves "git fetch" can be told to serve
commits that are not at the tip of any ref, as long as they are
reachable from a ref, with uploadpack.allowReachableSHA1InWant
configuration variable.

* fm/fetch-raw-sha1:
upload-pack: optionally allow fetching reachable sha1
upload-pack: prepare to extend allow-tip-sha1-in-want
config.txt: clarify allowTipSHA1InWant with camelCase
---

diff --git a/.gitignore b/.gitignore
index a05241916c..422c5382c1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -184,6 +184,7 @@
 /test-delta
 /test-dump-cache-tree
 /test-dump-split-index
+/test-dump-untracked-cache
 /test-scrap-cache-tree
 /test-genrandom
 /test-hashmap
diff --git a/Documentation/RelNotes/2.3.8.txt b/Documentation/RelNotes/2.3.8.txt
new file mode 100644
index 0000000000..0b67268a96
--- /dev/null
+++ b/Documentation/RelNotes/2.3.8.txt
@@ -0,0 +1,22 @@
+Git v2.3.8 Release Notes
+========================
+
+Fixes since v2.3.7
+------------------
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/Documentation/RelNotes/2.4.1.txt b/Documentation/RelNotes/2.4.1.txt
new file mode 100644
index 0000000000..a65a6c5829
--- /dev/null
+++ b/Documentation/RelNotes/2.4.1.txt
@@ -0,0 +1,40 @@
+Git v2.4.1 Release Notes
+========================
+
+Fixes since v2.4
+----------------
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+
+ * "git cat-file bl $blob" failed to barf even though there is no
+   object type that is "bl".
+
+ * Teach the codepaths that read .gitignore and .gitattributes files
+   that these files encoded in UTF-8 may have UTF-8 BOM marker at the
+   beginning; this makes it in line with what we do for configuration
+   files already.
+
+ * Access to objects in repositories that borrow from another one on a
+   slow NFS server unnecessarily got more expensive due to recent code
+   becoming more cautious in a naive way not to lose objects to pruning.
+
+ * We avoid setting core.worktree when the repository location is the
+   ".git" directory directly at the top level of the working tree, but
+   the code misdetected the case in which the working tree is at the
+   root level of the filesystem (which arguably is a silly thing to
+   do, but still valid).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/Documentation/RelNotes/2.4.2.txt b/Documentation/RelNotes/2.4.2.txt
new file mode 100644
index 0000000000..250cdc423c
--- /dev/null
+++ b/Documentation/RelNotes/2.4.2.txt
@@ -0,0 +1,45 @@
+Git v2.4.2 Release Notes
+========================
+
+Fixes since v2.4.1
+------------------
+
+ * "git rev-list --objects $old --not --all" to see if everything that
+   is reachable from $old is already connected to the existing refs
+   was very inefficient.
+
+ * "hash-object --literally" introduced in v2.2 was not prepared to
+   take a really long object type name.
+
+ * "git rebase --quiet" was not quite quiet when there is nothing to
+   do.
+
+ * The completion for "log --decorate=" parameter value was incorrect.
+
+ * "filter-branch" corrupted commit log message that ends with an
+   incomplete line on platforms with some "sed" implementations that
+   munge such a line.  Work it around by avoiding to use "sed".
+
+ * "git daemon" fails to build from the source under NO_IPV6
+   configuration (regression in 2.4).
+
+ * "git stash pop/apply" forgot to make sure that not just the working
+   tree is clean but also the index is clean. The latter is important
+   as a stash application can conflict and the index will be used for
+   conflict resolution.
+
+ * We have prepended $GIT_EXEC_PATH and the path "git" is installed in
+   (typically "/usr/bin") to $PATH when invoking subprograms and hooks
+   for almost eternity, but the original use case the latter tried to
+   support was semi-bogus (i.e. install git to /opt/foo/git and run it
+   without having /opt/foo on $PATH), and more importantly it has
+   become less and less relevant as Git grew more mainstream (i.e. the
+   users would _want_ to have it on their $PATH).  Stop prepending the
+   path in which "git" is installed to users' $PATH, as that would
+   interfere the command search order people depend on (e.g. they may
+   not like versions of programs that are unrelated to Git in /usr/bin
+   and want to override them by having different ones in /usr/local/bin
+   and have the latter directory earlier in their $PATH).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/Documentation/RelNotes/2.5.0.txt b/Documentation/RelNotes/2.5.0.txt
new file mode 100644
index 0000000000..3b2f62817b
--- /dev/null
+++ b/Documentation/RelNotes/2.5.0.txt
@@ -0,0 +1,344 @@
+Git 2.5 Release Notes
+=====================
+
+Updates since v2.4
+------------------
+
+Ports
+
+
+UI, Workflows & Features
+
+ * "git p4" now detects the filetype (e.g. binary) correctly even when
+   the files are opened exclusively.
+
+ * git p4 attempts to better handle branches in Perforce.
+
+ * "git p4" learned "--changes-block-size <n>" to read the changes in
+   chunks from Perforce, instead of making one call to "p4 changes"
+   that may trigger "too many rows scanned" error from Perforce.
+
+ * "git show-branch --topics HEAD" (with no other arguments) did not
+   do anything interesting.  Instead, contrast the given revision
+   against all the local branches by default.
+
+ * A replacement for contrib/workdir/git-new-workdir that does not
+   rely on symbolic links and make sharing of objects and refs safer
+   by making the borrowee and borrowers aware of each other.
+
+ * Tweak the sample "store" backend of the credential helper to honor
+   XDG configuration file locations when specified.
+
+ * A heuristic to help the "git <cmd> <revs> <pathspec>" command line
+   convention to catch mistyped paths is to make sure all the non-rev
+   parameters in the later part of the command line are names of the
+   files in the working tree, but that means "git grep $str -- \*.c"
+   must always be disambiguated with "--", because nobody sane will
+   create a file whose name literally is asterisk-dot-see.  Loosen the
+   heuristic to declare that with a wildcard string the user likely
+   meant to give us a pathspec.
+
+ * "git merge FETCH_HEAD" learned that the previous "git fetch" could
+   be to create an Octopus merge, i.e. recording multiple branches
+   that are not marked as "not-for-merge"; this allows us to lose an
+   old style invocation "git merge <msg> HEAD $commits..." in the
+   implementation of "git pull" script; the old style syntax can now
+   be deprecated.
+
+ * Help us to find broken test script that splits the body part of the
+   test by mistaken use of wrong kind of quotes.
+   (merge d93d5d5 jc/test-prereq-validate later to maint).
+
+ * Developer support to automatically detect broken &&-chain in the
+   test scripts is now turned on by default.
+   (merge 92b269f jk/test-chain-lint later to maint).
+
+ * Filter scripts were run with SIGPIPE disabled on the Git side,
+   expecting that they may not read what Git feeds them to filter.
+   We however treated a filter that does not read its input fully
+   before exiting as an error.
+
+   This changes semantics, but arguably in a good way.  If a filter
+   can produce its output without consuming its input using whatever
+   magic, we now let it do so, instead of diagnosing it as a
+   programming error.
+
+ * Instead of dying immediately upon failing to obtain a lock, the
+   locking (of refs etc) retries after a short while with backoff.
+
+ * Introduce http.<url>.SSLCipherList configuration variable to tweak
+   the list of cipher suite to be used with libcURL when talking with
+   https:// sites.
+
+ * "git subtree" script (in contrib/) used "echo -n" to produce
+   progress messages in a non-portable way.
+
+ * "git subtree" script (in contrib/) does not have --squash option
+   when pushing, but the documentation and help text pretended as if
+   it did.
+
+ * The Git subcommand completion (in contrib/) listed credential
+   helpers among candidates, which is not something the end user would
+   invoke interactively.
+
+ * The index file can be taught with "update-index --untracked-cache"
+   to optionally remember already seen untracked files, in order to
+   speed up "git status" in a working tree with tons of cruft.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * "unsigned char [20]" used throughout the code to represent object
+   names are being converted into a semi-opaque "struct object_id".
+   This effort is expected to interfere with other topics in flight,
+   but hopefully will give us one extra level of abstraction in the
+   end, when completed.
+
+ * Catch a programmer mistake to feed a pointer not an array to
+   ARRAY_SIZE() macro, by using a couple of GCC extensions.
+   (merge 89c855e ep/do-not-feed-a-pointer-to-array-size later to maint).
+
+ * Some error messages in "git config" were emitted without calling
+   the usual error() facility.
+
+ * When "add--interactive" splits a hunk into two overlapping hunks
+   and then let the user choose only one, it sometimes feeds an
+   incorrect patch text to "git apply".  Add tests to demonstrate
+   this.
+
+   I have a slight suspicion that this may be $gmane/87202 coming back
+   and biting us (I seem to have said "let's run with this and see
+   what happens" back then).
+
+ * More line-ending tests.
+
+ * An earlier rewrite to use strbuf_getwholeline() instead of fgets(3)
+   to read packed-refs file revealed that the former is unacceptably
+   inefficient.
+
+ * The refs API uses ref_lock struct which had its own "int fd", even
+   though the same file descriptor was in the lock struct it contains.
+   Clean-up the code to lose this redundant field.
+
+ * Add the "--allow-unknown-type" option to "cat-file" to allow
+   inspecting loose objects of an experimental or a broken type.
+
+ * Many long-running operations show progress eye-candy, even when
+   they are later backgrounded.  Hide the eye-candy when the process
+   is sent to the background instead.
+   (merge 9a9a41d lm/squelch-bg-progress later to maint).
+
+ * There was a dead code that used to handle "git pull --tags" and
+   show special-cased error message, which was made irrelevant when
+   the semantics of the option changed back in Git 1.9 days.
+   (merge 19d122b pt/pull-tags-error-diag later to maint).
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.4
+----------------
+
+Unless otherwise noted, all the fixes since v2.4 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * Git 2.4 broke setting verbosity and progress levels on "git clone"
+   with native transports.
+   (merge 822f0c4 mh/clone-verbosity-fix later to maint).
+
+ * "git add -e" did not allow the user to abort the operation by
+   killing the editor.
+   (merge cb64800 jk/add-e-kill-editor later to maint).
+
+ * Memory usage of "git index-pack" has been trimmed by tens of
+   per-cent.
+   (merge c6458e6 nd/slim-index-pack-memory-usage later to maint).
+
+ * "git rev-list --objects $old --not --all" to see if everything that
+   is reachable from $old is already connected to the existing refs
+   was very inefficient.
+   (merge b6e8a3b jk/still-interesting later to maint).
+
+ * "hash-object --literally" introduced in v2.2 was not prepared to
+   take a really long object type name.
+   (merge 1427a7f jc/hash-object later to maint).
+
+ * "git rebase --quiet" was not quite quiet when there is nothing to
+   do.
+   (merge 22946a9 jk/rebase-quiet-noop later to maint).
+
+ * The completion for "log --decorate=" parameter value was incorrect.
+   (merge af16bda sg/complete-decorate-full-not-long later to maint).
+
+ * "filter-branch" corrupted commit log message that ends with an
+   incomplete line on platforms with some "sed" implementations that
+   munge such a line.  Work it around by avoiding to use "sed".
+   (merge df06201 jk/filter-branch-use-of-sed-on-incomplete-line later to maint).
+
+ * "git daemon" fails to build from the source under NO_IPV6
+   configuration (regression in 2.4).
+   (merge d358f77 jc/daemon-no-ipv6-for-2.4.1 later to maint).
+
+ * Some time ago, "git blame" (incorrectly) lost the convert_to_git()
+   call when synthesizing a fake "tip" commit that represents the
+   state in the working tree, which broke folks who record the history
+   with LF line ending to make their project portable across platforms
+   while terminating lines in their working tree files with CRLF for
+   their platform.
+   (merge 4bf256d tb/blame-resurrect-convert-to-git later to maint).
+
+ * We avoid setting core.worktree when the repository location is the
+   ".git" directory directly at the top level of the working tree, but
+   the code misdetected the case in which the working tree is at the
+   root level of the filesystem (which arguably is a silly thing to
+   do, but still valid).
+   (merge 84ccad8 jk/init-core-worktree-at-root later to maint).
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+   (merge f6e6362 jc/epochtime-wo-tz later to maint).
+
+ * Access to objects in repositories that borrow from another one on a
+   slow NFS server unnecessarily got more expensive due to recent code
+   becoming more cautious in a naive way not to lose objects to pruning.
+   (merge ee1c6c3 jk/prune-mtime later to maint).
+
+ * The codepaths that read .gitignore and .gitattributes files have been
+   taught that these files encoded in UTF-8 may have UTF-8 BOM marker at
+   the beginning; this makes it in line with what we do for configuration
+   files already.
+   (merge 27547e5 cn/bom-in-gitignore later to maint).
+
+ * a few helper scripts in the test suite did not report errors
+   correctly.
+   (merge de248e9 ep/fix-test-lib-functions-report later to maint).
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+   (merge 7e11052 oh/fix-config-default-user-name-section later to maint).
+
+ * "git cat-file bl $blob" failed to barf even though there is no
+   object type that is "bl".
+   (merge b7994af jk/type-from-string-gently later to maint).
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+   (merge 0615173 jc/diff-no-index-d-f later to maint).
+
+ * "git rebase -i" moved the "current" command from "todo" to "done" a
+   bit too prematurely, losing a step when a "pick" did not even start.
+   (merge 8cbc57c ph/rebase-i-redo later to maint).
+
+ * The connection initiation code for "ssh" transport tried to absorb
+   differences between the stock "ssh" and Putty-supplied "plink" and
+   its derivatives, but the logic to tell that we are using "plink"
+   variants were too loose and falsely triggered when "plink" appeared
+   anywhere in the path (e.g. "/home/me/bin/uplink/ssh").
+   (merge baaf233 bc/connect-plink later to maint).
+
+ * "git stash pop/apply" forgot to make sure that not just the working
+   tree is clean but also the index is clean. The latter is important
+   as a stash application can conflict and the index will be used for
+   conflict resolution.
+   (merge ed178ef jk/stash-require-clean-index later to maint).
+
+ * We have prepended $GIT_EXEC_PATH and the path "git" is installed in
+   (typically "/usr/bin") to $PATH when invoking subprograms and hooks
+   for almost eternity, but the original use case the latter tried to
+   support was semi-bogus (i.e. install git to /opt/foo/git and run it
+   without having /opt/foo on $PATH), and more importantly it has
+   become less and less relevant as Git grew more mainstream (i.e. the
+   users would _want_ to have it on their $PATH).  Stop prepending the
+   path in which "git" is installed to users' $PATH, as that would
+   interfere the command search order people depend on (e.g. they may
+   not like versions of programs that are unrelated to Git in /usr/bin
+   and want to override them by having different ones in /usr/local/bin
+   and have the latter directory earlier in their $PATH).
+   (merge a0b4507 jk/git-no-more-argv0-path-munging later to maint).
+
+ * core.excludesfile (defaulting to $XDG_HOME/git/ignore) is supposed
+   to be overridden by repository-specific .git/info/exclude file, but
+   the order was swapped from the beginning. This belatedly fixes it.
+   (merge 099d2d8 jc/gitignore-precedence later to maint).
+
+ * After "git add -N", the path appeared in output of "git diff HEAD"
+   and "git diff --cached HEAD", leading "git status" to classify it
+   as "Changes to be committed".  Such a path, however, is not yet to
+   be scheduled to be committed.  "git diff" showed the change to the
+   path as modification, not as a "new file", in the header of its
+   output.
+
+   Treat such paths as "yet to be added to the index but Git already
+   know about them"; "git diff HEAD" and "git diff --cached HEAD"
+   should not talk about them, and "git diff" should show them as new
+   files yet to be added to the index.
+   (merge d95d728 nd/diff-i-t-a later to maint).
+
+ * There was a commented-out (instead of being marked to expect
+   failure) test that documented a breakage that was fixed since the
+   test was written; turn it into a proper test.
+   (merge 66d2e04 sb/t1020-cleanup later to maint).
+
+ * The "log --decorate" enhancement in Git 2.4 that shows the commit
+   at the tip of the current branch e.g. "HEAD -> master", did not
+   work with --decorate=full.
+   (merge 429ad20 mg/log-decorate-HEAD later to maint).
+
+ * The ref API did not handle cases where 'refs/heads/xyzzy/frotz' is
+   removed at the same time as 'refs/heads/xyzzy' is added (or vice
+   versa) very well.
+   (merge c628edf mh/ref-directory-file later to maint).
+
+ * Multi-ref transaction support we merged a few releases ago
+   unnecessarily kept many file descriptors open, risking to fail with
+   resource exhaustion.  This is for 2.4.x track.
+   (merge 185ce3a mh/write-refs-sooner-2.4 later to maint).
+
+ * "git bundle verify" did not diagnose extra parameters on the
+   command line.
+   (merge 7886cfa ps/bundle-verify-arg later to maint).
+
+ * Various documentation mark-up fixes to make the output more
+   consistent in general and also make AsciiDoctor (an alternative
+   formatter) happier.
+   (merge d0258b9 jk/asciidoc-markup-fix later to maint).
+   (merge ad3967a jk/stripspace-asciidoctor-fix later to maint).
+   (merge 975e382 ja/tutorial-asciidoctor-fix later to maint).
+
+ * The code to read pack-bitmap wanted to allocate a few hundred
+   pointers to a structure, but by mistake allocated and leaked memory
+   enough to hold that many actual structures.  Correct the allocation
+   size and also have it on stack, as it is small enough.
+   (merge 599dc76 rs/plug-leak-in-pack-bitmaps later to maint).
+
+ * The pull.ff configuration was supposed to override the merge.ff
+   configuration, but it didn't.
+   (merge db9bb28 pt/pull-ff-vs-merge-ff later to maint).
+
+ * "git pull --log" and "git pull --no-log" worked as expected, but
+   "git pull --log=20" did not.
+   (merge 5061a44 pt/pull-log-n later to maint).
+
+ * "git rerere forget" in a repository without rerere enabled gave a
+   cryptic error message; it should be a silent no-op instead.
+   (merge 0544574 jk/rerere-forget-check-enabled later to maint).
+
+ * Code cleanups and documentation updates.
+   (merge 0269f96 mm/usage-log-l-can-take-regex later to maint).
+   (merge 64f2589 nd/t1509-chroot-test later to maint).
+   (merge f86a374 sb/test-bitmap-free-at-end later to maint).
+   (merge 05bfc7d sb/line-log-plug-pairdiff-leak later to maint).
+   (merge 846e5df pt/xdg-config-path later to maint).
+   (merge 1154aa4 jc/plug-fmt-merge-msg-leak later to maint).
+   (merge 319b678 jk/sha1-file-reduce-useless-warnings later to maint).
+   (merge 9a35c14 fg/document-commit-message-stripping later to maint).
+   (merge bbf431c ps/doc-packfile-vs-pack-file later to maint).
+   (merge 309a9e3 jk/skip-http-tests-under-no-curl later to maint).
+   (merge ccd593c dl/branch-error-message later to maint).
diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt
index b299b59023..a09969ba08 100644
--- a/Documentation/blame-options.txt
+++ b/Documentation/blame-options.txt
@@ -10,7 +10,7 @@
 	Include additional statistics at the end of blame output.
 
 -L <start>,<end>::
--L :<regex>::
+-L :<funcname>::
 	Annotate only the given line range. May be specified multiple times.
 	Overlapping ranges are allowed.
 +
diff --git a/Documentation/cmd-list.perl b/Documentation/cmd-list.perl
index 04f99778d8..5aa73cfe45 100755
--- a/Documentation/cmd-list.perl
+++ b/Documentation/cmd-list.perl
@@ -38,6 +38,10 @@ sub format_one {
 	}
 }
 
+while (<>) {
+	last if /^### command list/;
+}
+
 my %cmds = ();
 for (sort <>) {
 	next if /^#/;
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 980520b655..4d21ce1647 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -453,6 +453,8 @@ false), while all other repositories are assumed to be bare (bare
 
 core.worktree::
 	Set the path to the root of the working tree.
+	If GIT_COMMON_DIR environment variable is set, core.worktree
+	is ignored and not used for determining the root of working tree.
 	This can be overridden by the GIT_WORK_TREE environment
 	variable and the '--work-tree' command-line option.
 	The value can be an absolute path or relative to the path to
@@ -622,6 +624,12 @@ core.commentChar::
 If set to "auto", `git-commit` would select a character that is not
 the beginning character of any line in existing commit messages.
 
+core.packedRefsTimeout::
+	The length of time, in milliseconds, to retry when trying to
+	lock the `packed-refs` file. Value 0 means not to retry at
+	all; -1 means to try indefinitely. Default is 1000 (i.e.,
+	retry for 1 second).
+
 sequence.editor::
 	Text editor used by `git rebase -i` for editing the rebase instruction file.
 	The value is meant to be interpreted by the shell when it is used.
@@ -1274,6 +1282,13 @@ gc.pruneExpire::
 	"now" may be used to disable this  grace period and always prune
 	unreachable objects immediately.
 
+gc.pruneWorktreesExpire::
+	When 'git gc' is run, it will call
+	'prune --worktrees --expire 3.months.ago'.
+	Override the grace period with this config variable. The value
+	"now" may be used to disable the grace period and prune
+	$GIT_DIR/worktrees immediately.
+
 gc.reflogExpire::
 gc.<pattern>.reflogExpire::
 	'git reflog expire' removes reflog entries older than
@@ -1560,6 +1575,19 @@ http.saveCookies::
 	If set, store cookies received during requests to the file specified by
 	http.cookieFile. Has no effect if http.cookieFile is unset.
 
+http.sslCipherList::
+  A list of SSL ciphers to use when negotiating an SSL connection.
+  The available ciphers depend on whether libcurl was built against
+  NSS or OpenSSL and the particular configuration of the crypto
+  library in use.  Internally this sets the 'CURLOPT_SSL_CIPHER_LIST'
+  option; see the libcurl documentation for more details on the format
+  of this list.
++
+Can be overridden by the 'GIT_SSL_CIPHER_LIST' environment variable.
+To force git to use libcurl's default cipher list and ignore any
+explicit http.sslCipherList option, set 'GIT_SSL_CIPHER_LIST' to the
+empty string.
+
 http.sslVerify::
 	Whether to verify the SSL certificate when fetching or pushing
 	over HTTPS. Can be overridden by the 'GIT_SSL_NO_VERIFY' environment
@@ -2033,7 +2061,7 @@ pull.ff::
 	a case (equivalent to giving the `--no-ff` option from the command
 	line). When set to `only`, only such fast-forward merges are
 	allowed (equivalent to giving the `--ff-only` option from the
-	command line).
+	command line). This setting overrides `merge.ff` when pulling.
 
 pull.rebase::
 	When true, rebase branches on top of the fetched branch, instead
@@ -2270,18 +2298,18 @@ remote.<name>.skipFetchAll::
 
 remote.<name>.receivepack::
 	The default program to execute on the remote side when pushing.  See
-	option \--receive-pack of linkgit:git-push[1].
+	option --receive-pack of linkgit:git-push[1].
 
 remote.<name>.uploadpack::
 	The default program to execute on the remote side when fetching.  See
-	option \--upload-pack of linkgit:git-fetch-pack[1].
+	option --upload-pack of linkgit:git-fetch-pack[1].
 
 remote.<name>.tagOpt::
-	Setting this value to \--no-tags disables automatic tag following when
-	fetching from remote <name>. Setting it to \--tags will fetch every
+	Setting this value to --no-tags disables automatic tag following when
+	fetching from remote <name>. Setting it to --tags will fetch every
 	tag from remote <name>, even if they are not reachable from remote
 	branch heads. Passing these flags directly to linkgit:git-fetch[1] can
-	override this setting. See options \--tags and \--no-tags of
+	override this setting. See options --tags and --no-tags of
 	linkgit:git-fetch[1].
 
 remote.<name>.vcs::
diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt
index 843a20bac2..bcf54da82a 100644
--- a/Documentation/diff-generate-patch.txt
+++ b/Documentation/diff-generate-patch.txt
@@ -77,7 +77,7 @@ combined diff format
 Any diff-generating command can take the `-c` or `--cc` option to
 produce a 'combined diff' when showing a merge. This is the default
 format when showing merges with linkgit:git-diff[1] or
-linkgit:git-show[1]. Note also that you can give the `-m' option to any
+linkgit:git-show[1]. Note also that you can give the `-m` option to any
 of these commands to force generation of diffs with individual parents
 of a merge.
 
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index ccd499867b..3ad6404dbc 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -23,7 +23,9 @@ ifndef::git-format-patch[]
 -u::
 --patch::
 	Generate patch (see section on generating patches).
-	{git-diff? This is the default.}
+ifdef::git-diff[]
+	This is the default.
+endif::git-diff[]
 endif::git-format-patch[]
 
 -s::
@@ -41,8 +43,19 @@ endif::git-format-patch[]
 
 ifndef::git-format-patch[]
 --raw::
-	Generate the raw format.
-	{git-diff-core? This is the default.}
+ifndef::git-log[]
+	Generate the diff in raw format.
+ifdef::git-diff-core[]
+	This is the default.
+endif::git-diff-core[]
+endif::git-log[]
+ifdef::git-log[]
+	For each commit, show a summary of changes using the raw diff
+	format. See the "RAW OUTPUT FORMAT" section of
+	linkgit:git-diff[1]. This is different from showing the log
+	itself in raw format, which you can achieve with
+	`--format=raw`.
+endif::git-log[]
 endif::git-format-patch[]
 
 ifndef::git-format-patch[]
diff --git a/Documentation/git-add.txt b/Documentation/git-add.txt
index f2eb9076d7..fe5282f130 100644
--- a/Documentation/git-add.txt
+++ b/Documentation/git-add.txt
@@ -93,7 +93,8 @@ This effectively runs `add --interactive`, but bypasses the
 initial command menu and directly jumps to the `patch` subcommand.
 See ``Interactive mode'' for details.
 
--e, \--edit::
+-e::
+--edit::
 	Open the diff vs. the index in an editor and let the user
 	edit it.  After the editor was closed, adjust the hunk headers
 	and apply the patch to the index.
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
index f6a16f4300..319ab4cb08 100644
--- a/Documentation/git-cat-file.txt
+++ b/Documentation/git-cat-file.txt
@@ -9,8 +9,8 @@ git-cat-file - Provide content or type and size information for repository objec
 SYNOPSIS
 --------
 [verse]
-'git cat-file' (-t | -s | -e | -p | <type> | --textconv ) <object>
-'git cat-file' (--batch | --batch-check) < <list-of-objects>
+'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv ) <object>
+'git cat-file' (--batch | --batch-check) [--follow-symlinks] < <list-of-objects>
 
 DESCRIPTION
 -----------
@@ -69,6 +69,65 @@ OPTIONS
 	not be combined with any other options or arguments.  See the
 	section `BATCH OUTPUT` below for details.
 
+--allow-unknown-type::
+	Allow -s or -t to query broken/corrupt objects of unknown type.
+
+--follow-symlinks::
+	With --batch or --batch-check, follow symlinks inside the
+	repository when requesting objects with extended SHA-1
+	expressions of the form tree-ish:path-in-tree.  Instead of
+	providing output about the link itself, provide output about
+	the linked-to object.  If a symlink points outside the
+	tree-ish (e.g. a link to /foo or a root-level link to ../foo),
+	the portion of the link which is outside the tree will be
+	printed.
++
+This option does not (currently) work correctly when an object in the
+index is specified (e.g. `:link` instead of `HEAD:link`) rather than
+one in the tree.
++
+This option cannot (currently) be used unless `--batch` or
+`--batch-check` is used.
++
+For example, consider a git repository containing:
++
+--
+	f: a file containing "hello\n"
+	link: a symlink to f
+	dir/link: a symlink to ../f
+	plink: a symlink to ../f
+	alink: a symlink to /etc/passwd
+--
++
+For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print
++
+--
+	ce013625030ba8dba906f756967f9e9ca394464a blob 6
+--
++
+And `echo HEAD:link | git cat-file --batch --follow-symlinks` would
+print the same thing, as would `HEAD:dir/link`, as they both point at
+`HEAD:f`.
++
+Without `--follow-symlinks`, these would print data about the symlink
+itself.  In the case of `HEAD:link`, you would see
++
+--
+	4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1
+--
++
+Both `plink` and `alink` point outside the tree, so they would
+respectively print:
++
+--
+	symlink 4
+	../f
+
+	symlink 11
+	/etc/passwd
+--
+
+
 OUTPUT
 ------
 If '-t' is specified, one of the <type>.
@@ -148,6 +207,47 @@ the repository, then `cat-file` will ignore any custom format and print:
 <object> SP missing LF
 ------------
 
+If --follow-symlinks is used, and a symlink in the repository points
+outside the repository, then `cat-file` will ignore any custom format
+and print:
+
+------------
+symlink SP <size> LF
+<symlink> LF
+------------
+
+The symlink will either be absolute (beginning with a /), or relative
+to the tree root.  For instance, if dir/link points to ../../foo, then
+<symlink> will be ../foo.  <size> is the size of the symlink in bytes.
+
+If --follow-symlinks is used, the following error messages will be
+displayed:
+
+------------
+<object> SP missing LF
+------------
+is printed when the initial symlink requested does not exist.
+
+------------
+dangling SP <size> LF
+<object> LF
+------------
+is printed when the initial symlink exists, but something that
+it (transitive-of) points to does not.
+
+------------
+loop SP <size> LF
+<object> LF
+------------
+is printed for symlink loops (or any symlinks that
+require more than 40 link resolutions to resolve).
+
+------------
+notdir SP <size> LF
+<object> LF
+------------
+is printed when, during symlink resolution, a file is used as a
+directory name.
 
 CAVEATS
 -------
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index d5041082e8..d263a5652f 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -225,6 +225,19 @@ This means that you can use `git checkout -p` to selectively discard
 edits from your current working tree. See the ``Interactive Mode''
 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
 
+--to=<path>::
+	Check out a branch in a separate working directory at
+	`<path>`. A new working directory is linked to the current
+	repository, sharing everything except working directory
+	specific files such as HEAD, index... See "MULTIPLE WORKING
+	TREES" section for more information.
+
+--ignore-other-worktrees::
+	`git checkout` refuses when the wanted ref is already checked
+	out by another worktree. This option makes it check the ref
+	out anyway. In other words, the ref can be held by more than one
+	worktree.
+
 <branch>::
 	Branch to checkout; if it refers to a branch (i.e., a name that,
 	when prepended with "refs/heads/", is a valid ref), then that
@@ -388,6 +401,71 @@ $ git reflog -2 HEAD # or
 $ git log -g -2 HEAD
 ------------
 
+MULTIPLE WORKING TREES
+----------------------
+
+A git repository can support multiple working trees, allowing you to check
+out more than one branch at a time.  With `git checkout --to` a new working
+tree is associated with the repository.  This new working tree is called a
+"linked working tree" as opposed to the "main working tree" prepared by "git
+init" or "git clone".  A repository has one main working tree (if it's not a
+bare repository) and zero or more linked working trees.
+
+Each linked working tree has a private sub-directory in the repository's
+$GIT_DIR/worktrees directory.  The private sub-directory's name is usually
+the base name of the linked working tree's path, possibly appended with a
+number to make it unique.  For example, when `$GIT_DIR=/path/main/.git` the
+command `git checkout --to /path/other/test-next next` creates the linked
+working tree in `/path/other/test-next` and also creates a
+`$GIT_DIR/worktrees/test-next` directory (or `$GIT_DIR/worktrees/test-next1`
+if `test-next` is already taken).
+
+Within a linked working tree, $GIT_DIR is set to point to this private
+directory (e.g. `/path/main/.git/worktrees/test-next` in the example) and
+$GIT_COMMON_DIR is set to point back to the main working tree's $GIT_DIR
+(e.g. `/path/main/.git`). These settings are made in a `.git` file located at
+the top directory of the linked working tree.
+
+Path resolution via `git rev-parse --git-path` uses either
+$GIT_DIR or $GIT_COMMON_DIR depending on the path. For example, in the
+linked working tree `git rev-parse --git-path HEAD` returns
+`/path/main/.git/worktrees/test-next/HEAD` (not
+`/path/other/test-next/.git/HEAD` or `/path/main/.git/HEAD`) while `git
+rev-parse --git-path refs/heads/master` uses
+$GIT_COMMON_DIR and returns `/path/main/.git/refs/heads/master`,
+since refs are shared across all working trees.
+
+See linkgit:gitrepository-layout[5] for more information. The rule of
+thumb is do not make any assumption about whether a path belongs to
+$GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
+inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
+
+When you are done with a linked working tree you can simply delete it.
+The working tree's entry in the repository's $GIT_DIR/worktrees
+directory will eventually be removed automatically (see
+`gc.pruneworktreesexpire` in linkgit::git-config[1]), or you can run
+`git prune --worktrees` in the main or any linked working tree to
+clean up any stale entries in $GIT_DIR/worktrees.
+
+If you move a linked working directory to another file system, or
+within a file system that does not support hard links, you need to run
+at least one git command inside the linked working directory
+(e.g. `git status`) in order to update its entry in $GIT_DIR/worktrees
+so that it does not get automatically removed.
+
+To prevent a $GIT_DIR/worktrees entry from from being pruned (which
+can be useful in some situations, such as when the
+entry's working tree is stored on a portable device), add a file named
+'locked' to the entry's directory. The file contains the reason in
+plain text. For example, if a linked working tree's `.git` file points
+to `/path/main/.git/worktrees/test-next` then a file named
+`/path/main/.git/worktrees/test-next/locked` will prevent the
+`test-next` entry from being pruned.  See
+linkgit:gitrepository-layout[5] for details.
+
+Multiple checkout support for submodules is incomplete. It is NOT
+recommended to make multiple checkouts of a superproject.
+
 EXAMPLES
 --------
 
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 617e29b38b..904dafa0f7 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -94,7 +94,7 @@ OPTIONS
 --reset-author::
 	When used with -C/-c/--amend options, or when committing after a
 	a conflicting cherry-pick, declare that the authorship of the
-	resulting commit now belongs of the committer. This also renews
+	resulting commit now belongs to the committer. This also renews
 	the author timestamp.
 
 --short::
@@ -180,8 +180,8 @@ OPTIONS
 +
 --
 strip::
-	Strip leading and trailing empty lines, trailing whitespace, and
-	#commentary and collapse consecutive empty lines.
+	Strip leading and trailing empty lines, trailing whitespace,
+	commentary and collapse consecutive empty lines.
 whitespace::
 	Same as `strip` except #commentary is not removed.
 verbatim::
@@ -282,8 +282,11 @@ configuration variable documented in linkgit:git-config[1].
 --verbose::
 	Show unified diff between the HEAD commit and what
 	would be committed at the bottom of the commit message
-	template.  Note that this diff output doesn't have its
-	lines prefixed with '#'.
+	template to help the user describe the commit by reminding
+	what changes the commit has.
+	Note that this diff output doesn't have its
+	lines prefixed with '#'. This diff will not be a part
+	of the commit message.
 +
 If specified twice, show in addition the unified diff between
 what would be committed and the worktree files, i.e. the unstaged
diff --git a/Documentation/git-credential-store.txt b/Documentation/git-credential-store.txt
index bc97071e76..e3c8f276b1 100644
--- a/Documentation/git-credential-store.txt
+++ b/Documentation/git-credential-store.txt
@@ -31,10 +31,41 @@ OPTIONS
 
 --file=<path>::
 
-	Use `<path>` to store credentials. The file will have its
+	Use `<path>` to lookup and store credentials. The file will have its
 	filesystem permissions set to prevent other users on the system
 	from reading it, but will not be encrypted or otherwise
-	protected. Defaults to `~/.git-credentials`.
+	protected. If not specified, credentials will be searched for from
+	`~/.git-credentials` and `$XDG_CONFIG_HOME/git/credentials`, and
+	credentials will be written to `~/.git-credentials` if it exists, or
+	`$XDG_CONFIG_HOME/git/credentials` if it exists and the former does
+	not. See also <<FILES>>.
+
+[[FILES]]
+FILES
+-----
+
+If not set explicitly with '--file', there are two files where
+git-credential-store will search for credentials in order of precedence:
+
+~/.git-credentials::
+	User-specific credentials file.
+
+$XDG_CONFIG_HOME/git/credentials::
+	Second user-specific credentials file. If '$XDG_CONFIG_HOME' is not set
+	or empty, `$HOME/.config/git/credentials` will be used. Any credentials
+	stored in this file will not be used if `~/.git-credentials` has a
+	matching credential as well. It is a good idea not to create this file
+	if you sometimes use older versions of Git that do not support it.
+
+For credential lookups, the files are read in the order given above, with the
+first matching credential found taking precedence over credentials found in
+files further down the list.
+
+Credential storage will by default write to the first existing file in the
+list. If none of these files exist, `~/.git-credentials` will be created and
+written to.
+
+When erasing credentials, matching credentials will be erased from all files.
 
 EXAMPLES
 --------
diff --git a/Documentation/git-fast-export.txt b/Documentation/git-fast-export.txt
index 929e496af8..ed57c684db 100644
--- a/Documentation/git-fast-export.txt
+++ b/Documentation/git-fast-export.txt
@@ -67,17 +67,17 @@ produced incorrect results if you gave these options.
 	have been completed, or to save the marks table across
 	incremental runs.  As <file> is only opened and truncated
 	at completion, the same path can also be safely given to
-	\--import-marks.
+	--import-marks.
 	The file will not be written if no new object has been
 	marked/exported.
 
 --import-marks=<file>::
 	Before processing any input, load the marks specified in
 	<file>.  The input file must exist, must be readable, and
-	must use the same format as produced by \--export-marks.
+	must use the same format as produced by --export-marks.
 +
 Any commits that have already been marked will not be exported again.
-If the backend uses a similar \--import-marks file, this allows for
+If the backend uses a similar --import-marks file, this allows for
 incremental bidirectional exporting of the repository by keeping the
 marks the same across runs.
 
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 690fed3ea4..fd32895255 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -42,13 +42,13 @@ OPTIONS
 --quiet::
 	Disable all non-fatal output, making fast-import silent when it
 	is successful.  This option disables the output shown by
-	\--stats.
+	--stats.
 
 --stats::
 	Display some basic statistics about the objects fast-import has
 	created, the packfiles they were stored into, and the
 	memory used by fast-import during this run.  Showing this output
-	is currently the default, but can be disabled with \--quiet.
+	is currently the default, but can be disabled with --quiet.
 
 Options for Frontends
 ~~~~~~~~~~~~~~~~~~~~~
@@ -81,12 +81,12 @@ Locations of Marks Files
 	have been completed, or to save the marks table across
 	incremental runs.  As <file> is only opened and truncated
 	at checkpoint (or completion) the same path can also be
-	safely given to \--import-marks.
+	safely given to --import-marks.
 
 --import-marks=<file>::
 	Before processing any input, load the marks specified in
 	<file>.  The input file must exist, must be readable, and
-	must use the same format as produced by \--export-marks.
+	must use the same format as produced by --export-marks.
 	Multiple options may be supplied to import more than one
 	set of marks.  If a mark is defined to different values,
 	the last file wins.
@@ -179,8 +179,8 @@ fast-forward update, fast-import will skip updating that ref and instead
 prints a warning message.  fast-import will always attempt to update all
 branch refs, and does not stop on the first failure.
 
-Branch updates can be forced with \--force, but it's recommended that
-this only be used on an otherwise quiet repository.  Using \--force
+Branch updates can be forced with --force, but it's recommended that
+this only be used on an otherwise quiet repository.  Using --force
 is not necessary for an initial import into an empty repository.
 
 
@@ -231,11 +231,11 @@ Date Formats
 ~~~~~~~~~~~~
 The following date formats are supported.  A frontend should select
 the format it will use for this import by passing the format name
-in the \--date-format=<fmt> command-line option.
+in the --date-format=<fmt> command-line option.
 
 `raw`::
 	This is the Git native format and is `<time> SP <offutc>`.
-	It is also fast-import's default format, if \--date-format was
+	It is also fast-import's default format, if --date-format was
 	not specified.
 +
 The time of the event is specified by `<time>` as the number of
@@ -437,7 +437,7 @@ the email address from the other fields in the line.  Note that
 of bytes, except `LT`, `GT` and `LF`.  `<name>` is typically UTF-8 encoded.
 
 The time of the change is specified by `<when>` using the date format
-that was selected by the \--date-format=<fmt> command-line option.
+that was selected by the --date-format=<fmt> command-line option.
 See ``Date Formats'' above for the set of supported formats, and
 their syntax.
 
@@ -600,7 +600,7 @@ be removed from the branch.
 See `filemodify` above for a detailed description of `<path>`.
 
 `filecopy`
-^^^^^^^^^^^^
+^^^^^^^^^^
 Recursively copies an existing file or subdirectory to a different
 location within the branch.  The existing file or directory must
 exist.  If the destination exists it will be completely replaced
@@ -888,7 +888,7 @@ save out all current branch refs, tags and marks.
 ....
 
 Note that fast-import automatically switches packfiles when the current
-packfile reaches \--max-pack-size, or 4 GiB, whichever limit is
+packfile reaches --max-pack-size, or 4 GiB, whichever limit is
 smaller.  During an automatic packfile switch fast-import does not update
 the branch refs, tags or marks.
 
@@ -1226,7 +1226,7 @@ users of fast-import, and are offered here as suggestions.
 Use One Mark Per Commit
 ~~~~~~~~~~~~~~~~~~~~~~~
 When doing a repository conversion, use a unique mark per commit
-(`mark :<n>`) and supply the \--export-marks option on the command
+(`mark :<n>`) and supply the --export-marks option on the command
 line.  fast-import will dump a file which lists every mark and the Git
 object SHA-1 that corresponds to it.  If the frontend can tie
 the marks back to the source repository, it is easy to verify the
@@ -1291,7 +1291,7 @@ even for considerably large projects (100,000+ commits).
 
 However repacking the repository is necessary to improve data
 locality and access performance.  It can also take hours on extremely
-large projects (especially if -f and a large \--window parameter is
+large projects (especially if -f and a large --window parameter is
 used).  Since repacking is safe to run alongside readers and writers,
 run the repack in the background and let it finish when it finishes.
 There is no reason to wait to explore your new Git project!
@@ -1305,7 +1305,7 @@ Repacking Historical Data
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 If you are repacking very old imported data (e.g. older than the
 last year), consider expending some extra CPU time and supplying
-\--window=50 (or higher) when you run 'git repack'.
+--window=50 (or higher) when you run 'git repack'.
 This will take longer, but will also produce a smaller packfile.
 You only need to expend the effort once, and everyone using your
 project will benefit from the smaller repository.
@@ -1407,7 +1407,7 @@ branch, their in-memory storage size can grow to a considerable size
 fast-import automatically moves active branches to inactive status based on
 a simple least-recently-used algorithm.  The LRU chain is updated on
 each `commit` command.  The maximum number of active branches can be
-increased or decreased on the command line with \--active-branches=.
+increased or decreased on the command line with --active-branches=.
 
 per active tree
 ~~~~~~~~~~~~~~~
diff --git a/Documentation/git-fetch-pack.txt b/Documentation/git-fetch-pack.txt
index 93b5067946..8680f45f8d 100644
--- a/Documentation/git-fetch-pack.txt
+++ b/Documentation/git-fetch-pack.txt
@@ -80,7 +80,7 @@ be in a separate packet, and the list must end with a flush packet.
 	the things up in .bash_profile).
 
 --exec=<git-upload-pack>::
-	Same as \--upload-pack=<git-upload-pack>.
+	Same as --upload-pack=<git-upload-pack>.
 
 --depth=<n>::
 	Limit fetching to ancestor-chains not longer than n.
diff --git a/Documentation/git-hash-object.txt b/Documentation/git-hash-object.txt
index 02c1f12685..0c75f3b610 100644
--- a/Documentation/git-hash-object.txt
+++ b/Documentation/git-hash-object.txt
@@ -9,7 +9,7 @@ git-hash-object - Compute object ID and optionally creates a blob from a file
 SYNOPSIS
 --------
 [verse]
-'git hash-object' [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin] [--] <file>...
+'git hash-object' [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin [--literally]] [--] <file>...
 'git hash-object' [-t <type>] [-w] --stdin-paths [--no-filters] < <list-of-paths>
 
 DESCRIPTION
@@ -51,7 +51,13 @@ OPTIONS
 	Hash the contents as is, ignoring any input filter that would
 	have been chosen by the attributes mechanism, including the end-of-line
 	conversion. If the file is read from standard input then this
-	is always implied, unless the --path option is given.
+	is always implied, unless the `--path` option is given.
+
+--literally::
+	Allow `--stdin` to hash any garbage into a loose object which might not
+	otherwise pass standard object parsing or git-fsck checks. Useful for
+	stress-testing Git itself or reproducing characteristics of corrupt or
+	bogus objects encountered in the wild.
 
 GIT
 ---
diff --git a/Documentation/git-http-backend.txt b/Documentation/git-http-backend.txt
index d422ba4b59..9268fb6b1e 100644
--- a/Documentation/git-http-backend.txt
+++ b/Documentation/git-http-backend.txt
@@ -65,8 +65,8 @@ automatically by the web server.
 
 EXAMPLES
 --------
-All of the following examples map 'http://$hostname/git/foo/bar.git'
-to '/var/www/git/foo/bar.git'.
+All of the following examples map `http://$hostname/git/foo/bar.git`
+to `/var/www/git/foo/bar.git`.
 
 Apache 2.x::
 	Ensure mod_cgi, mod_alias, and mod_env are enabled, set
@@ -255,6 +255,15 @@ The GIT_HTTP_EXPORT_ALL environmental variable may be passed to
 'git-http-backend' to bypass the check for the "git-daemon-export-ok"
 file in each repository before allowing export of that repository.
 
+The `GIT_HTTP_MAX_REQUEST_BUFFER` environment variable (or the
+`http.maxRequestBuffer` config variable) may be set to change the
+largest ref negotiation request that git will handle during a fetch; any
+fetch requiring a larger buffer will not succeed.  This value should not
+normally need to be changed, but may be helpful if you are fetching from
+a repository with an extremely large number of refs.  The value can be
+specified with a unit (e.g., `100M` for 100 megabytes). The default is
+10 megabytes.
+
 The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and
 GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}',
 ensuring that any reflogs created by 'git-receive-pack' contain some
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 18bc716a0c..5692945a0b 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -62,9 +62,9 @@ produced by `--stat`, etc.
 	output by allowing them to allocate space in advance.
 
 -L <start>,<end>:<file>::
--L :<regex>:<file>::
+-L :<funcname>:<file>::
 	Trace the evolution of the line range given by "<start>,<end>"
-	(or the funcname regex <regex>) within the <file>.  You may
+	(or the function name regex <funcname>) within the <file>.  You may
 	not give any pathspec limiters.  This is currently limited to
 	a walk starting from a single revision, i.e., you may only
 	give zero or one positive revision arguments.
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 1f94908e3c..273a1009be 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -104,6 +104,10 @@ commit or stash your changes before running 'git merge'.
 If no commit is given from the command line, merge the remote-tracking
 branches that the current branch is configured to use as its upstream.
 See also the configuration section of this manual page.
++
+When `FETCH_HEAD` (and no other commit) is specified, the branches
+recorded in the `.git/FETCH_HEAD` file by the previous invocation
+of `git fetch` for merging are merged to the current branch.
 
 
 PRE-MERGE CHECKS
diff --git a/Documentation/git-p4.txt b/Documentation/git-p4.txt
index a1664b9f68..82aa5d6073 100644
--- a/Documentation/git-p4.txt
+++ b/Documentation/git-p4.txt
@@ -225,9 +225,20 @@ Git repository:
 	they can find the p4 branches in refs/heads.
 
 --max-changes <n>::
-	Limit the number of imported changes to 'n'.  Useful to
-	limit the amount of history when using the '@all' p4 revision
-	specifier.
+	Import at most 'n' changes, rather than the entire range of
+	changes included in the given revision specifier. A typical
+	usage would be use '@all' as the revision specifier, but then
+	to use '--max-changes 1000' to import only the last 1000
+	revisions rather than the entire revision history.
+
+--changes-block-size <n>::
+	The internal block size to use when converting a revision
+	specifier such as '@all' into a list of specific change
+	numbers. Instead of using a single call to 'p4 changes' to
+	find the full list of changes for the conversion, there are a
+	sequence of calls to 'p4 changes -m', each of which requests
+	one block of changes of the given size. The default block size
+	is 500, which should usually be suitable.
 
 --keep-path::
 	The mapping of file names from the p4 depot path to Git, by
diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index c2f76fb1ea..bbea5294ca 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt
@@ -192,7 +192,7 @@ self-contained. Use `git index-pack --fix-thin`
 
 --shallow::
 	Optimize a pack that will be provided to a client with a shallow
-	repository.  This option, combined with \--thin, can result in a
+	repository.  This option, combined with --thin, can result in a
 	smaller pack at the cost of speed.
 
 --delta-base-offset::
diff --git a/Documentation/git-prune.txt b/Documentation/git-prune.txt
index 7a493c80f7..1cf3bed4ab 100644
--- a/Documentation/git-prune.txt
+++ b/Documentation/git-prune.txt
@@ -48,6 +48,9 @@ OPTIONS
 --expire <time>::
 	Only expire loose objects older than <time>.
 
+--worktrees::
+	Prune dead working tree information in $GIT_DIR/worktrees.
+
 <head>...::
 	In addition to objects
 	reachable from any of our references, keep objects
diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
index 863c30c4c2..135d810b7a 100644
--- a/Documentation/git-push.txt
+++ b/Documentation/git-push.txt
@@ -265,8 +265,8 @@ origin +master` to force a push to the `master` branch). See the
 
 --[no-]verify::
 	Toggle the pre-push hook (see linkgit:githooks[5]).  The
-	default is \--verify, giving the hook a chance to prevent the
-	push.  With \--no-verify, the hook is bypassed completely.
+	default is --verify, giving the hook a chance to prevent the
+	push.  With --no-verify, the hook is bypassed completely.
 
 
 include::urls-remotes.txt[]
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 47984e84ed..1d01baa5fc 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -80,7 +80,7 @@ remain the checked-out branch.
 If the upstream branch already contains a change you have made (e.g.,
 because you mailed a patch which was applied upstream), then that commit
 will be skipped. For example, running `git rebase master` on the
-following history (in which A' and A introduce the same set of changes,
+following history (in which `A'` and `A` introduce the same set of changes,
 but have different committer information):
 
 ------------
diff --git a/Documentation/git-rev-list.txt b/Documentation/git-rev-list.txt
index 5b119220bf..b10ea60833 100644
--- a/Documentation/git-rev-list.txt
+++ b/Documentation/git-rev-list.txt
@@ -9,54 +9,54 @@ git-rev-list - Lists commit objects in reverse chronological order
 SYNOPSIS
 --------
 [verse]
-'git rev-list' [ \--max-count=<number> ]
-	     [ \--skip=<number> ]
-	     [ \--max-age=<timestamp> ]
-	     [ \--min-age=<timestamp> ]
-	     [ \--sparse ]
-	     [ \--merges ]
-	     [ \--no-merges ]
-	     [ \--min-parents=<number> ]
-	     [ \--no-min-parents ]
-	     [ \--max-parents=<number> ]
-	     [ \--no-max-parents ]
-	     [ \--first-parent ]
-	     [ \--remove-empty ]
-	     [ \--full-history ]
-	     [ \--not ]
-	     [ \--all ]
-	     [ \--branches[=<pattern>] ]
-	     [ \--tags[=<pattern>] ]
-	     [ \--remotes[=<pattern>] ]
-	     [ \--glob=<glob-pattern> ]
-	     [ \--ignore-missing ]
-	     [ \--stdin ]
-	     [ \--quiet ]
-	     [ \--topo-order ]
-	     [ \--parents ]
-	     [ \--timestamp ]
-	     [ \--left-right ]
-	     [ \--left-only ]
-	     [ \--right-only ]
-	     [ \--cherry-mark ]
-	     [ \--cherry-pick ]
-	     [ \--encoding=<encoding> ]
-	     [ \--(author|committer|grep)=<pattern> ]
-	     [ \--regexp-ignore-case | -i ]
-	     [ \--extended-regexp | -E ]
-	     [ \--fixed-strings | -F ]
-	     [ \--date=(local|relative|default|iso|iso-strict|rfc|short) ]
-	     [ [ \--objects | \--objects-edge | \--objects-edge-aggressive ]
-	       [ \--unpacked ] ]
-	     [ \--pretty | \--header ]
-	     [ \--bisect ]
-	     [ \--bisect-vars ]
-	     [ \--bisect-all ]
-	     [ \--merge ]
-	     [ \--reverse ]
-	     [ \--walk-reflogs ]
-	     [ \--no-walk ] [ \--do-walk ]
-	     [ \--use-bitmap-index ]
+'git rev-list' [ --max-count=<number> ]
+	     [ --skip=<number> ]
+	     [ --max-age=<timestamp> ]
+	     [ --min-age=<timestamp> ]
+	     [ --sparse ]
+	     [ --merges ]
+	     [ --no-merges ]
+	     [ --min-parents=<number> ]
+	     [ --no-min-parents ]
+	     [ --max-parents=<number> ]
+	     [ --no-max-parents ]
+	     [ --first-parent ]
+	     [ --remove-empty ]
+	     [ --full-history ]
+	     [ --not ]
+	     [ --all ]
+	     [ --branches[=<pattern>] ]
+	     [ --tags[=<pattern>] ]
+	     [ --remotes[=<pattern>] ]
+	     [ --glob=<glob-pattern> ]
+	     [ --ignore-missing ]
+	     [ --stdin ]
+	     [ --quiet ]
+	     [ --topo-order ]
+	     [ --parents ]
+	     [ --timestamp ]
+	     [ --left-right ]
+	     [ --left-only ]
+	     [ --right-only ]
+	     [ --cherry-mark ]
+	     [ --cherry-pick ]
+	     [ --encoding=<encoding> ]
+	     [ --(author|committer|grep)=<pattern> ]
+	     [ --regexp-ignore-case | -i ]
+	     [ --extended-regexp | -E ]
+	     [ --fixed-strings | -F ]
+	     [ --date=(local|relative|default|iso|iso-strict|rfc|short) ]
+	     [ [ --objects | --objects-edge | --objects-edge-aggressive ]
+	       [ --unpacked ] ]
+	     [ --pretty | --header ]
+	     [ --bisect ]
+	     [ --bisect-vars ]
+	     [ --bisect-all ]
+	     [ --merge ]
+	     [ --reverse ]
+	     [ --walk-reflogs ]
+	     [ --no-walk ] [ --do-walk ]
+	     [ --use-bitmap-index ]
 	     <commit>... [ \-- <paths>... ]
 
 DESCRIPTION
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index d6de42f74e..c483100e75 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -102,7 +102,7 @@ eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
 +
 If you want to make sure that the output actually names an object in
 your object database and/or can be used as a specific type of object
-you require, you can add "\^{type}" peeling operator to the parameter.
+you require, you can add the `^{type}` peeling operator to the parameter.
 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
 names an existing object that is a commit-ish (i.e. a commit, or an
 annotated tag that points at a commit).  To make sure that `$VAR`
@@ -147,7 +147,7 @@ can be used.
 	form as close to the original input as possible.
 
 --symbolic-full-name::
-	This is similar to \--symbolic, but it omits input that
+	This is similar to --symbolic, but it omits input that
 	are not refs (i.e. branch or tag names; or more
 	explicitly disambiguating "heads/master" form, when you
 	want to name the "master" branch when there is an
@@ -216,6 +216,9 @@ If `$GIT_DIR` is not defined and the current directory
 is not detected to lie in a Git repository or work tree
 print a message to stderr and exit with nonzero status.
 
+--git-common-dir::
+	Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
+
 --is-inside-git-dir::
 	When the current working directory is below the repository
 	directory print "true", otherwise "false".
@@ -233,6 +236,13 @@ print a message to stderr and exit with nonzero status.
 	repository.  If <path> is a gitfile then the resolved path
 	to the real repository is printed.
 
+--git-path <path>::
+	Resolve "$GIT_DIR/<path>" and takes other path relocation
+	variables such as $GIT_OBJECT_DIRECTORY,
+	$GIT_INDEX_FILE... into account. For example, if
+	$GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
+	--git-path objects/abc" returns /foo/bar/abc.
+
 --show-cdup::
 	When the command is invoked from a subdirectory, show the
 	path of the top-level directory relative to the current
diff --git a/Documentation/git-send-pack.txt b/Documentation/git-send-pack.txt
index 45c7725dc3..b5d09f79ee 100644
--- a/Documentation/git-send-pack.txt
+++ b/Documentation/git-send-pack.txt
@@ -29,7 +29,7 @@ OPTIONS
 	a directory on the default $PATH.
 
 --exec=<git-receive-pack>::
-	Same as \--receive-pack=<git-receive-pack>.
+	Same as --receive-pack=<git-receive-pack>.
 
 --all::
 	Instead of explicitly specifying which refs to update,
diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index 4e617e6979..82a4125a2d 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt
@@ -22,7 +22,7 @@ presents the merge commit in a special format as produced by
 For tags, it shows the tag message and the referenced objects.
 
 For trees, it shows the names (equivalent to 'git ls-tree'
-with \--name-only).
+with --name-only).
 
 For plain blobs, it shows the plain contents.
 
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index 5221f950ce..335f312335 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -66,7 +66,10 @@ When `-u` option is not used, untracked files and directories are
 shown (i.e. the same as specifying `normal`), to help you avoid
 forgetting to add newly created files.  Because it takes extra work
 to find untracked files in the filesystem, this mode may take some
-time in a large working tree.  You can use `no` to have `git status`
+time in a large working tree.
+Consider enabling untracked cache and split index if supported (see
+`git update-index --untracked-cache` and `git update-index
+--split-index`), Otherwise you can use `no` to have `git status`
 return more quickly without showing untracked files.
 +
 The default can be changed using the status.showUntrackedFiles
diff --git a/Documentation/git-stripspace.txt b/Documentation/git-stripspace.txt
index 6c6e989074..60328d5d08 100644
--- a/Documentation/git-stripspace.txt
+++ b/Documentation/git-stripspace.txt
@@ -49,7 +49,7 @@ EXAMPLES
 
 Given the following noisy input with '$' indicating the end of a line:
 
---------
+---------
 |A brief introduction   $
 |   $
 |$
@@ -65,7 +65,7 @@ Given the following noisy input with '$' indicating the end of a line:
 
 Use 'git stripspace' with no arguments to obtain:
 
---------
+---------
 |A brief introduction$
 |$
 |A new paragraph$
@@ -79,7 +79,7 @@ Use 'git stripspace' with no arguments to obtain:
 
 Use 'git stripspace --strip-comments' to obtain:
 
---------
+---------
 |A brief introduction$
 |$
 |A new paragraph$
diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index 39e9a181cc..11d1e2fc66 100644
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -70,8 +70,8 @@ COMMANDS
 --username=<user>;;
 	For transports that SVN handles authentication for (http,
 	https, and plain svn), specify the username.  For other
-	transports (e.g. svn+ssh://), you must include the username in
-	the URL, e.g. svn+ssh://foo@svn.bar.com/project
+	transports (e.g. `svn+ssh://`), you must include the username in
+	the URL, e.g. `svn+ssh://foo@svn.bar.com/project`
 --prefix=<prefix>;;
 	This allows one to specify a prefix which is prepended
 	to the names of remotes if trunk/branches/tags are
@@ -279,9 +279,9 @@ first have already been pushed into SVN.
 	Ask the user to confirm that a patch set should actually be sent to SVN.
 	For each patch, one may answer "yes" (accept this patch), "no" (discard this
 	patch), "all" (accept all patches), or "quit".
-	+
-	'git svn dcommit' returns immediately if answer is "no" or "quit", without
-	committing anything to SVN.
++
+'git svn dcommit' returns immediately if answer is "no" or "quit", without
+committing anything to SVN.
 
 'branch'::
 	Create a branch in the SVN repository.
diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index f5b267e1e3..034d10d633 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -158,7 +158,7 @@ This option is only applicable when listing tags without annotation lines.
 CONFIGURATION
 -------------
 By default, 'git tag' in sign-with-default mode (-s) will use your
-committer identity (of the form "Your Name <\your@email.address>") to
+committer identity (of the form `Your Name <your@email.address>`) to
 find a key.  If you want to use a different default key, you can specify
 it in the repository configuration as follows:
 
diff --git a/Documentation/git-unpack-objects.txt b/Documentation/git-unpack-objects.txt
index 12cb108b85..07d432988f 100644
--- a/Documentation/git-unpack-objects.txt
+++ b/Documentation/git-unpack-objects.txt
@@ -9,7 +9,7 @@ git-unpack-objects - Unpack objects from a packed archive
 SYNOPSIS
 --------
 [verse]
-'git unpack-objects' [-n] [-q] [-r] [--strict] < <pack-file>
+'git unpack-objects' [-n] [-q] [-r] [--strict] < <packfile>
 
 
 DESCRIPTION
@@ -19,8 +19,8 @@ the objects contained within and writing them into the repository in
 "loose" (one object per file) format.
 
 Objects that already exist in the repository will *not* be unpacked
-from the pack-file.  Therefore, nothing will be unpacked if you use
-this command on a pack-file that exists within the target repository.
+from the packfile.  Therefore, nothing will be unpacked if you use
+this command on a packfile that exists within the target repository.
 
 See linkgit:git-repack[1] for options to generate
 new packs and replace existing ones.
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index aff01798cd..1a296bc29a 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -170,6 +170,20 @@ may not support it yet.
 	the shared index file. This mode is designed for very large
 	indexes that take a significant amount of time to read or write.
 
+--untracked-cache::
+--no-untracked-cache::
+	Enable or disable untracked cache extension. This could speed
+	up for commands that involve determining untracked files such
+	as `git status`. The underlying operating system and file
+	system must change `st_mtime` field of a directory if files
+	are added or deleted in that directory.
+
+--force-untracked-cache::
+	For safety, `--untracked-cache` performs tests on the working
+	directory to make sure untracked cache can be used. These
+	tests can take a few seconds. `--force-untracked-cache` can be
+	used to skip the tests.
+
 \--::
 	Do not interpret any more arguments as options.
 
diff --git a/Documentation/git-verify-pack.txt b/Documentation/git-verify-pack.txt
index 526ba7be9c..61ca6d04c2 100644
--- a/Documentation/git-verify-pack.txt
+++ b/Documentation/git-verify-pack.txt
@@ -40,7 +40,7 @@ OUTPUT FORMAT
 -------------
 When specifying the -v option the format used is:
 
-	SHA-1 type size size-in-pack-file offset-in-packfile
+	SHA-1 type size size-in-packfile offset-in-packfile
 
 for objects that are not deltified in the pack, and
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index c71e818cf4..ccc12b2806 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -43,14 +43,17 @@ unreleased) version of Git, that is available from the 'master'
 branch of the `git.git` repository.
 Documentation for older releases are available here:
 
-* link:v2.4.0/git.html[documentation for release 2.4]
+* link:v2.4.2/git.html[documentation for release 2.4.2]
 
 * release notes for
+  link:RelNotes/2.4.2.txt[2.4.2],
+  link:RelNotes/2.4.1.txt[2.4.1],
   link:RelNotes/2.4.0.txt[2.4].
 
-* link:v2.3.7/git.html[documentation for release 2.3.7]
+* link:v2.3.8/git.html[documentation for release 2.3.8]
 
 * release notes for
+  link:RelNotes/2.3.8.txt[2.3.8],
   link:RelNotes/2.3.7.txt[2.3.7],
   link:RelNotes/2.3.6.txt[2.3.6],
   link:RelNotes/2.3.5.txt[2.3.5],
@@ -833,6 +836,15 @@ Git so take care if using Cogito etc.
 	an explicit repository directory set via 'GIT_DIR' or on the
 	command line.
 
+'GIT_COMMON_DIR'::
+	If this variable is set to a path, non-worktree files that are
+	normally in $GIT_DIR will be taken from this path
+	instead. Worktree-specific files such as HEAD or index are
+	taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and
+	the section 'MULTIPLE CHECKOUT MODE' in linkgit:checkout[1]
+	details. This variable has lower precedence than other path
+	variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...
+
 Git Commits
 ~~~~~~~~~~~
 'GIT_AUTHOR_NAME'::
diff --git a/Documentation/gitcore-tutorial.txt b/Documentation/gitcore-tutorial.txt
index 8475c07932..36e9ab3e16 100644
--- a/Documentation/gitcore-tutorial.txt
+++ b/Documentation/gitcore-tutorial.txt
@@ -259,7 +259,7 @@ index 557db03..263414f 100644
 @@ -1 +1,2 @@
  Hello World
 +It's a new day for git
-----
+------------
 
 i.e. the diff of the change we caused by adding another line to `hello`.
 
diff --git a/Documentation/gitdiffcore.txt b/Documentation/gitdiffcore.txt
index c8b3e51c84..c579593e55 100644
--- a/Documentation/gitdiffcore.txt
+++ b/Documentation/gitdiffcore.txt
@@ -28,8 +28,8 @@ The 'git diff-{asterisk}' family works by first comparing two sets of
 files:
 
  - 'git diff-index' compares contents of a "tree" object and the
-   working directory (when '\--cached' flag is not used) or a
-   "tree" object and the index file (when '\--cached' flag is
+   working directory (when '--cached' flag is not used) or a
+   "tree" object and the index file (when '--cached' flag is
    used);
 
  - 'git diff-files' compares contents of the index file and the
@@ -142,7 +142,7 @@ merges these filepairs and creates:
 
 When the "-C" option is used, the original contents of modified files,
 and deleted files (and also unmodified files, if the
-"\--find-copies-harder" option is used) are considered as candidates
+"--find-copies-harder" option is used) are considered as candidates
 of the source files in rename/copy operation.  If the input were like
 these filepairs, that talk about a modified file fileY and a newly
 created file file0:
diff --git a/Documentation/gitk.txt b/Documentation/gitk.txt
index 7ae50aa26a..6ade002176 100644
--- a/Documentation/gitk.txt
+++ b/Documentation/gitk.txt
@@ -99,10 +99,10 @@ linkgit:git-rev-list[1] for a complete list.
 	detailed explanation.)
 
 -L<start>,<end>:<file>::
--L:<regex>:<file>::
+-L:<funcname>:<file>::
 
 	Trace the evolution of the line range given by "<start>,<end>"
-	(or the funcname regex <regex>) within the <file>.  You may
+	(or the function name regex <funcname>) within the <file>.  You may
 	not give any pathspec limiters.  This is currently limited to
 	a walk starting from a single revision, i.e., you may only
 	give zero or one positive revision arguments.
diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
index 8edf72cf53..82e2d15435 100644
--- a/Documentation/gitremote-helpers.txt
+++ b/Documentation/gitremote-helpers.txt
@@ -408,14 +408,14 @@ set by Git if the remote helper has the 'option' capability.
 	of <n> correspond to the number of -v flags passed on the
 	command line.
 
-'option progress' \{'true'|'false'\}::
+'option progress' {'true'|'false'}::
 	Enables (or disables) progress messages displayed by the
 	transport helper during a command.
 
 'option depth' <depth>::
 	Deepens the history of a shallow repository.
 
-'option followtags' \{'true'|'false'\}::
+'option followtags' {'true'|'false'}::
 	If enabled the helper should automatically fetch annotated
 	tag objects if the object the tag points at was transferred
 	during the fetch command.  If the tag is not fetched by
@@ -423,7 +423,7 @@ set by Git if the remote helper has the 'option' capability.
 	ask for the tag specifically.  Some helpers may be able to
 	use this option to avoid a second network connection.
 
-'option dry-run' \{'true'|'false'\}:
+'option dry-run' {'true'|'false'}:
 	If true, pretend the operation completed successfully,
 	but don't actually change any repository data.	For most
 	helpers this only applies to the 'push', if supported.
@@ -434,18 +434,18 @@ set by Git if the remote helper has the 'option' capability.
 	must not rely on this option being set before
 	connect request occurs.
 
-'option check-connectivity' \{'true'|'false'\}::
+'option check-connectivity' {'true'|'false'}::
 	Request the helper to check connectivity of a clone.
 
-'option force' \{'true'|'false'\}::
+'option force' {'true'|'false'}::
 	Request the helper to perform a force update.  Defaults to
 	'false'.
 
-'option cloning \{'true'|'false'\}::
+'option cloning {'true'|'false'}::
 	Notify the helper this is a clone request (i.e. the current
 	repository is guaranteed empty).
 
-'option update-shallow \{'true'|'false'\}::
+'option update-shallow {'true'|'false'}::
 	Allow to extend .git/shallow if the new refs require it.
 
 SEE ALSO
diff --git a/Documentation/gitrepository-layout.txt b/Documentation/gitrepository-layout.txt
index 79653f3134..7173b38830 100644
--- a/Documentation/gitrepository-layout.txt
+++ b/Documentation/gitrepository-layout.txt
@@ -46,6 +46,9 @@ of incomplete object store is not suitable to be published for
 use with dumb transports but otherwise is OK as long as
 `objects/info/alternates` points at the object stores it
 borrows from.
++
+This directory is ignored if $GIT_COMMON_DIR is set and
+"$GIT_COMMON_DIR/objects" will be used instead.
 
 objects/[0-9a-f][0-9a-f]::
 	A newly created object is stored in its own file.
@@ -92,7 +95,8 @@ refs::
 	References are stored in subdirectories of this
 	directory.  The 'git prune' command knows to preserve
 	objects reachable from refs found in this directory and
-	its subdirectories.
+	its subdirectories. This directory is ignored if $GIT_COMMON_DIR
+	is set and "$GIT_COMMON_DIR/refs" will be used instead.
 
 refs/heads/`name`::
 	records tip-of-the-tree commit objects of branch `name`
@@ -114,7 +118,8 @@ refs/replace/`<obj-sha1>`::
 packed-refs::
 	records the same information as refs/heads/, refs/tags/,
 	and friends record in a more efficient way.  See
-	linkgit:git-pack-refs[1].
+	linkgit:git-pack-refs[1]. This file is ignored if $GIT_COMMON_DIR
+	is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
 
 HEAD::
 	A symref (see glossary) to the `refs/heads/` namespace
@@ -133,6 +138,11 @@ being a symref to point at the current branch.  Such a state
 is often called 'detached HEAD.'  See linkgit:git-checkout[1]
 for details.
 
+config::
+	Repository specific configuration file. This file is ignored
+	if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be
+	used instead.
+
 branches::
 	A slightly deprecated way to store shorthands to be used
 	to specify a URL to 'git fetch', 'git pull' and 'git push'.
@@ -140,7 +150,10 @@ branches::
 	'name' can be given to these commands in place of
 	'repository' argument.  See the REMOTES section in
 	linkgit:git-fetch[1] for details.  This mechanism is legacy
-	and not likely to be found in modern repositories.
+	and not likely to be found in modern repositories. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/branches" will be used instead.
+
 
 hooks::
 	Hooks are customization scripts used by various Git
@@ -149,7 +162,9 @@ hooks::
 	default.  To enable, the `.sample` suffix has to be
 	removed from the filename by renaming.
 	Read linkgit:githooks[5] for more details about
-	each hook.
+	each hook. This directory is ignored if $GIT_COMMON_DIR is set
+	and "$GIT_COMMON_DIR/hooks" will be used instead.
+
 
 index::
 	The current index file for the repository.  It is
@@ -161,7 +176,8 @@ sharedindex.<SHA-1>::
 
 info::
 	Additional information about the repository is recorded
-	in this directory.
+	in this directory. This directory is ignored if $GIT_COMMON_DIR
+	is set and "$GIT_COMMON_DIR/index" will be used instead.
 
 info/refs::
 	This file helps dumb transports discover what refs are
@@ -201,12 +217,15 @@ remotes::
 	when interacting with remote repositories via 'git fetch',
 	'git pull' and 'git push' commands.  See the REMOTES section
 	in linkgit:git-fetch[1] for details.  This mechanism is legacy
-	and not likely to be found in modern repositories.
+	and not likely to be found in modern repositories. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/remotes" will be used instead.
 
 logs::
-	Records of changes made to refs are stored in this
-	directory.  See linkgit:git-update-ref[1]
-	for more information.
+	Records of changes made to refs are stored in this directory.
+	See linkgit:git-update-ref[1] for more information. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/logs" will be used instead.
 
 logs/refs/heads/`name`::
 	Records all changes made to the branch tip named `name`.
@@ -217,11 +236,46 @@ logs/refs/tags/`name`::
 shallow::
 	This is similar to `info/grafts` but is internally used
 	and maintained by shallow clone mechanism.  See `--depth`
-	option to linkgit:git-clone[1] and linkgit:git-fetch[1].
+	option to linkgit:git-clone[1] and linkgit:git-fetch[1]. This
+	file is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/shallow" will be used instead.
+
+commondir::
+	If this file exists, $GIT_COMMON_DIR (see linkgit:git[1]) will
+	be set to the path specified in this file if it is not
+	explicitly set. If the specified path is relative, it is
+	relative to $GIT_DIR. The repository with commondir is
+	incomplete without the repository pointed by "commondir".
 
 modules::
 	Contains the git-repositories of the submodules.
 
+worktrees::
+	Contains worktree specific information of linked
+	checkouts. Each subdirectory contains the worktree-related
+	part of a linked checkout. This directory is ignored if
+	$GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/worktrees" will be
+	used instead.
+
+worktrees/<id>/gitdir::
+	A text file containing the absolute path back to the .git file
+	that points to here. This is used to check if the linked
+	repository has been manually removed and there is no need to
+	keep this directory any more. mtime of this file should be
+	updated every time the linked repository is accessed.
+
+worktrees/<id>/locked::
+	If this file exists, the linked repository may be on a
+	portable device and not available. It does not mean that the
+	linked repository is gone and `worktrees/<id>` could be
+	removed. The file's content contains a reason string on why
+	the repository is locked.
+
+worktrees/<id>/link::
+	If this file exists, it is a hard link to the linked .git
+	file. It is used to detect if the linked repository is
+	manually removed.
+
 SEE ALSO
 --------
 linkgit:git-init[1],
diff --git a/Documentation/howto/new-command.txt b/Documentation/howto/new-command.txt
index d7de5a3e9e..6d772bd927 100644
--- a/Documentation/howto/new-command.txt
+++ b/Documentation/howto/new-command.txt
@@ -95,7 +95,9 @@ your language, document it in the INSTALL file.
 that categorizes commands by type, so they can be listed in appropriate
 subsections in the documentation's summary command list.  Add an entry
 for yours.  To understand the categories, look at git-commands.txt
-in the main directory.
+in the main directory.  If the new command is part of the typical Git
+workflow and you believe it common enough to be mentioned in 'git help',
+map this command to a common group in the column [common].
 
 7. Give the maintainer one paragraph to include in the RelNotes file
 to describe the new feature; a good place to do so is in the cover
diff --git a/Documentation/line-range-format.txt b/Documentation/line-range-format.txt
index d7f26039ca..829676ff98 100644
--- a/Documentation/line-range-format.txt
+++ b/Documentation/line-range-format.txt
@@ -22,8 +22,9 @@ This is only valid for <end> and will specify a number
 of lines before or after the line given by <start>.
 
 +
-If ``:<regex>'' is given in place of <start> and <end>, it denotes the range
-from the first funcname line that matches <regex>, up to the next
-funcname line. ``:<regex>'' searches from the end of the previous `-L` range,
-if any, otherwise from the start of file.
-``^:<regex>'' searches from the start of file.
+If ``:<funcname>'' is given in place of <start> and <end>, it is a
+regular expression that denotes the range from the first funcname line
+that matches <funcname>, up to the next funcname line. ``:<funcname>''
+searches from the end of the previous `-L` range, if any, otherwise
+from the start of file. ``^:<funcname>'' searches from the start of
+file.
diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index dcf7429a47..dc865cbb27 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -79,7 +79,10 @@ stored in the commit object.  Notably, the SHA-1s are
 displayed in full, regardless of whether --abbrev or
 --no-abbrev are used, and 'parents' information show the
 true parent commits, without taking grafts or history
-simplification into account.
+simplification into account. Note that this format affects the way
+commits are displayed, but not the way the diff is shown e.g. with
+`git log --raw`. To get full object names in a raw diff format,
+use `--no-abbrev`.
 
 * 'format:<string>'
 +
diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt
index 35112e4966..b7093af8b2 100644
--- a/Documentation/technical/index-format.txt
+++ b/Documentation/technical/index-format.txt
@@ -233,3 +233,65 @@ Git index format
   The remaining index entries after replaced ones will be added to the
   final index. These added entries are also sorted by entry name then
   stage.
+
+== Untracked cache
+
+  Untracked cache saves the untracked file list and necessary data to
+  verify the cache. The signature for this extension is { 'U', 'N',
+  'T', 'R' }.
+
+  The extension starts with
+
+  - A sequence of NUL-terminated strings, preceded by the size of the
+    sequence in variable width encoding. Each string describes the
+    environment where the cache can be used.
+
+  - Stat data of $GIT_DIR/info/exclude. See "Index entry" section from
+    ctime field until "file size".
+
+  - Stat data of core.excludesfile
+
+  - 32-bit dir_flags (see struct dir_struct)
+
+  - 160-bit SHA-1 of $GIT_DIR/info/exclude. Null SHA-1 means the file
+    does not exist.
+
+  - 160-bit SHA-1 of core.excludesfile. Null SHA-1 means the file does
+    not exist.
+
+  - NUL-terminated string of per-dir exclude file name. This usually
+    is ".gitignore".
+
+  - The number of following directory blocks, variable width
+    encoding. If this number is zero, the extension ends here with a
+    following NUL.
+
+  - A number of directory blocks in depth-first-search order, each
+    consists of
+
+    - The number of untracked entries, variable width encoding.
+
+    - The number of sub-directory blocks, variable width encoding.
+
+    - The directory name terminated by NUL.
+
+    - A number of untrached file/dir names terminated by NUL.
+
+The remaining data of each directory block is grouped by type:
+
+  - An ewah bitmap, the n-th bit marks whether the n-th directory has
+    valid untracked cache entries.
+
+  - An ewah bitmap, the n-th bit records "check-only" bit of
+    read_directory_recursive() for the n-th directory.
+
+  - An ewah bitmap, the n-th bit indicates whether SHA-1 and stat data
+    is valid for the n-th directory and exists in the next data.
+
+  - An array of stat data. The n-th data corresponds with the n-th
+    "one" bit in the previous ewah bitmap.
+
+  - An array of SHA-1. The n-th SHA-1 corresponds with the n-th "one" bit
+    in the previous ewah bitmap.
+
+  - One NUL.
diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt
index 462e20645f..fc09c63b32 100644
--- a/Documentation/technical/pack-protocol.txt
+++ b/Documentation/technical/pack-protocol.txt
@@ -465,7 +465,7 @@ contain all the objects that the server will need to complete the new
 references.
 
 ----
-  update-request    =  *shallow ( command-list | push-cert ) [pack-file]
+  update-request    =  *shallow ( command-list | push-cert ) [packfile]
 
   shallow           =  PKT-LINE("shallow" SP obj-id LF)
 
@@ -491,7 +491,7 @@ references.
 		      *PKT-LINE(gpg-signature-lines LF)
 		      PKT-LINE("push-cert-end" LF)
 
-  pack-file         = "PACK" 28*(OCTET)
+  packfile          = "PACK" 28*(OCTET)
 ----
 
 If the receiving end does not support delete-refs, the sending end MUST
@@ -502,11 +502,11 @@ MUST NOT send a push-cert command.  When a push-cert command is
 sent, command-list MUST NOT be sent; the commands recorded in the
 push certificate is used instead.
 
-The pack-file MUST NOT be sent if the only command used is 'delete'.
+The packfile MUST NOT be sent if the only command used is 'delete'.
 
-A pack-file MUST be sent if either create or update command is used,
+A packfile MUST be sent if either create or update command is used,
 even if the server already has all the necessary objects.  In this
-case the client MUST send an empty pack-file.   The only time this
+case the client MUST send an empty packfile.   The only time this
 is likely to happen is if the client is creating
 a new branch or a tag that points to an existing obj-id.
 
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 48aee9c417..bfb715d3c8 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.4.0
+DEF_VER=v2.4.0.GIT
 
 LF='
 '
diff --git a/Makefile b/Makefile
index 5f3987fe3b..54ec511dff 100644
--- a/Makefile
+++ b/Makefile
@@ -359,6 +359,8 @@ all::
 # compiler is detected to support it.
 #
 # Define HAVE_BSD_SYSCTL if your platform has a BSD-compatible sysctl function.
+#
+# Define HAVE_GETDELIM if your system has the getdelim() function.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -572,6 +574,7 @@ TEST_PROGRAMS_NEED_X += test-date
 TEST_PROGRAMS_NEED_X += test-delta
 TEST_PROGRAMS_NEED_X += test-dump-cache-tree
 TEST_PROGRAMS_NEED_X += test-dump-split-index
+TEST_PROGRAMS_NEED_X += test-dump-untracked-cache
 TEST_PROGRAMS_NEED_X += test-genrandom
 TEST_PROGRAMS_NEED_X += test-hashmap
 TEST_PROGRAMS_NEED_X += test-index-version
@@ -1437,6 +1440,10 @@ ifdef HAVE_BSD_SYSCTL
 	BASIC_CFLAGS += -DHAVE_BSD_SYSCTL
 endif
 
+ifdef HAVE_GETDELIM
+	BASIC_CFLAGS += -DHAVE_GETDELIM
+endif
+
 ifeq ($(TCLTK_PATH),)
 NO_TCLTK = NoThanks
 endif
@@ -1687,10 +1694,10 @@ $(BUILT_INS): git$X
 	ln -s $< $@ 2>/dev/null || \
 	cp $< $@
 
-common-cmds.h: ./generate-cmdlist.sh command-list.txt
+common-cmds.h: generate-cmdlist.perl command-list.txt
 
 common-cmds.h: $(wildcard Documentation/git-*.txt)
-	$(QUIET_GEN)./generate-cmdlist.sh > $@+ && mv $@+ $@
+	$(QUIET_GEN)$(PERL_PATH) generate-cmdlist.perl command-list.txt > $@+ && mv $@+ $@
 
 SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
 	$(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
@@ -2102,6 +2109,7 @@ GIT-BUILD-OPTIONS: FORCE
 	@echo PYTHON_PATH=\''$(subst ','\'',$(PYTHON_PATH_SQ))'\' >>$@
 	@echo TAR=\''$(subst ','\'',$(subst ','\'',$(TAR)))'\' >>$@
 	@echo NO_CURL=\''$(subst ','\'',$(subst ','\'',$(NO_CURL)))'\' >>$@
+	@echo NO_EXPAT=\''$(subst ','\'',$(subst ','\'',$(NO_EXPAT)))'\' >>$@
 	@echo USE_LIBPCRE=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE)))'\' >>$@
 	@echo NO_PERL=\''$(subst ','\'',$(subst ','\'',$(NO_PERL)))'\' >>$@
 	@echo NO_PYTHON=\''$(subst ','\'',$(subst ','\'',$(NO_PYTHON)))'\' >>$@
@@ -2447,7 +2455,7 @@ check-docs::
 		esac ; \
 		test -f "Documentation/$$v.txt" || \
 		echo "no doc: $$v"; \
-		sed -e '/^#/d' command-list.txt | \
+		sed -e '1,/^### command list/d' -e '/^#/d' command-list.txt | \
 		grep -q "^$$v[ 	]" || \
 		case "$$v" in \
 		git) ;; \
@@ -2455,7 +2463,8 @@ check-docs::
 		esac ; \
 	done; \
 	( \
-		sed -e '/^#/d' \
+		sed -e '1,/^### command list/d' \
+		    -e '/^#/d' \
 		    -e 's/[ 	].*//' \
 		    -e 's/^/listed /' command-list.txt; \
 		$(MAKE) -C Documentation print-man1 | \
diff --git a/RelNotes b/RelNotes
index 1addbec925..3295d667f3 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.4.0.txt
\ No newline at end of file
+Documentation/RelNotes/2.5.0.txt
\ No newline at end of file
diff --git a/archive-zip.c b/archive-zip.c
index ffb3535e93..ae3d67f9d3 100644
--- a/archive-zip.c
+++ b/archive-zip.c
@@ -448,12 +448,12 @@ static void write_zip_trailer(const unsigned char *sha1)
 	copy_le16(trailer.entries, zip_dir_entries);
 	copy_le32(trailer.size, zip_dir_offset);
 	copy_le32(trailer.offset, zip_offset);
-	copy_le16(trailer.comment_length, sha1 ? 40 : 0);
+	copy_le16(trailer.comment_length, sha1 ? GIT_SHA1_HEXSZ : 0);
 
 	write_or_die(1, zip_dir, zip_dir_offset);
 	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 	if (sha1)
-		write_or_die(1, sha1_to_hex(sha1), 40);
+		write_or_die(1, sha1_to_hex(sha1), GIT_SHA1_HEXSZ);
 }
 
 static void dos_time(time_t *time, int *dos_date, int *dos_time)
diff --git a/archive.c b/archive.c
index 96057ed830..d37c41daf2 100644
--- a/archive.c
+++ b/archive.c
@@ -101,7 +101,7 @@ static void setup_archive_check(struct git_attr_check *check)
 
 struct directory {
 	struct directory *up;
-	unsigned char sha1[20];
+	struct object_id oid;
 	int baselen, len;
 	unsigned mode;
 	int stage;
@@ -177,7 +177,7 @@ static void queue_directory(const unsigned char *sha1,
 	d->stage   = stage;
 	c->bottom  = d;
 	d->len = sprintf(d->path, "%.*s%s/", (int)base->len, base->buf, filename);
-	hashcpy(d->sha1, sha1);
+	hashcpy(d->oid.hash, sha1);
 }
 
 static int write_directory(struct archiver_context *c)
@@ -191,7 +191,7 @@ static int write_directory(struct archiver_context *c)
 	d->path[d->len - 1] = '\0'; /* no trailing slash */
 	ret =
 		write_directory(c) ||
-		write_archive_entry(d->sha1, d->path, d->baselen,
+		write_archive_entry(d->oid.hash, d->path, d->baselen,
 				    d->path + d->baselen, d->mode,
 				    d->stage, c) != READ_TREE_RECURSIVE;
 	free(d);
@@ -354,7 +354,7 @@ static void parse_treeish_arg(const char **argv,
 	time_t archive_time;
 	struct tree *tree;
 	const struct commit *commit;
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	/* Remotes are only allowed to fetch actual refs */
 	if (remote && !remote_allow_unreachable) {
@@ -362,15 +362,15 @@ static void parse_treeish_arg(const char **argv,
 		const char *colon = strchrnul(name, ':');
 		int refnamelen = colon - name;
 
-		if (!dwim_ref(name, refnamelen, sha1, &ref))
+		if (!dwim_ref(name, refnamelen, oid.hash, &ref))
 			die("no such ref: %.*s", refnamelen, name);
 		free(ref);
 	}
 
-	if (get_sha1(name, sha1))
+	if (get_sha1(name, oid.hash))
 		die("Not a valid object name");
 
-	commit = lookup_commit_reference_gently(sha1, 1);
+	commit = lookup_commit_reference_gently(oid.hash, 1);
 	if (commit) {
 		commit_sha1 = commit->object.sha1;
 		archive_time = commit->date;
@@ -379,21 +379,21 @@ static void parse_treeish_arg(const char **argv,
 		archive_time = time(NULL);
 	}
 
-	tree = parse_tree_indirect(sha1);
+	tree = parse_tree_indirect(oid.hash);
 	if (tree == NULL)
 		die("not a tree object");
 
 	if (prefix) {
-		unsigned char tree_sha1[20];
+		struct object_id tree_oid;
 		unsigned int mode;
 		int err;
 
 		err = get_tree_entry(tree->object.sha1, prefix,
-				     tree_sha1, &mode);
+				     tree_oid.hash, &mode);
 		if (err || !S_ISDIR(mode))
 			die("current working directory is untracked");
 
-		tree = parse_tree_indirect(tree_sha1);
+		tree = parse_tree_indirect(tree_oid.hash);
 	}
 	ar_args->tree = tree;
 	ar_args->commit_sha1 = commit_sha1;
diff --git a/attr.c b/attr.c
index 1f9eebd2dd..8f2ac6c88c 100644
--- a/attr.c
+++ b/attr.c
@@ -12,6 +12,7 @@
 #include "exec_cmd.h"
 #include "attr.h"
 #include "dir.h"
+#include "utf8.h"
 
 const char git_attr__true[] = "(builtin)true";
 const char git_attr__false[] = "\0(builtin)false";
@@ -379,8 +380,12 @@ static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 		return NULL;
 	}
 	res = xcalloc(1, sizeof(*res));
-	while (fgets(buf, sizeof(buf), fp))
-		handle_attr_line(res, buf, path, ++lineno, macro_ok);
+	while (fgets(buf, sizeof(buf), fp)) {
+		char *bufp = buf;
+		if (!lineno)
+			skip_utf8_bom(&bufp, strlen(bufp));
+		handle_attr_line(res, bufp, path, ++lineno, macro_ok);
+	}
 	fclose(fp);
 	return res;
 }
@@ -488,7 +493,6 @@ static int git_attr_system(void)
 static void bootstrap_attr_stack(void)
 {
 	struct attr_stack *elem;
-	char *xdg_attributes_file;
 
 	if (attr_stack)
 		return;
@@ -507,10 +511,8 @@ static void bootstrap_attr_stack(void)
 		}
 	}
 
-	if (!git_attributes_file) {
-		home_config_paths(NULL, &xdg_attributes_file, "attributes");
-		git_attributes_file = xdg_attributes_file;
-	}
+	if (!git_attributes_file)
+		git_attributes_file = xdg_config_home("attributes");
 	if (git_attributes_file) {
 		elem = read_attr_from_file(git_attributes_file, 1);
 		if (elem) {
diff --git a/bisect.c b/bisect.c
index 8c6d843699..10f5e57ef3 100644
--- a/bisect.c
+++ b/bisect.c
@@ -15,7 +15,7 @@
 static struct sha1_array good_revs;
 static struct sha1_array skipped_revs;
 
-static unsigned char *current_bad_sha1;
+static struct object_id *current_bad_oid;
 
 static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
 static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
@@ -404,8 +404,8 @@ static int register_ref(const char *refname, const unsigned char *sha1,
 			int flags, void *cb_data)
 {
 	if (!strcmp(refname, "bad")) {
-		current_bad_sha1 = xmalloc(20);
-		hashcpy(current_bad_sha1, sha1);
+		current_bad_oid = xmalloc(sizeof(*current_bad_oid));
+		hashcpy(current_bad_oid->hash, sha1);
 	} else if (starts_with(refname, "good-")) {
 		sha1_array_append(&good_revs, sha1);
 	} else if (starts_with(refname, "skip-")) {
@@ -564,7 +564,7 @@ static struct commit_list *skip_away(struct commit_list *list, int count)
 
 	for (i = 0; cur; cur = cur->next, i++) {
 		if (i == index) {
-			if (hashcmp(cur->item->object.sha1, current_bad_sha1))
+			if (hashcmp(cur->item->object.sha1, current_bad_oid->hash))
 				return cur;
 			if (previous)
 				return previous;
@@ -607,7 +607,7 @@ static void bisect_rev_setup(struct rev_info *revs, const char *prefix,
 
 	/* rev_argv.argv[0] will be ignored by setup_revisions */
 	argv_array_push(&rev_argv, "bisect_rev_setup");
-	argv_array_pushf(&rev_argv, bad_format, sha1_to_hex(current_bad_sha1));
+	argv_array_pushf(&rev_argv, bad_format, oid_to_hex(current_bad_oid));
 	for (i = 0; i < good_revs.nr; i++)
 		argv_array_pushf(&rev_argv, good_format,
 				 sha1_to_hex(good_revs.sha1[i]));
@@ -628,7 +628,7 @@ static void bisect_common(struct rev_info *revs)
 }
 
 static void exit_if_skipped_commits(struct commit_list *tried,
-				    const unsigned char *bad)
+				    const struct object_id *bad)
 {
 	if (!tried)
 		return;
@@ -637,12 +637,12 @@ static void exit_if_skipped_commits(struct commit_list *tried,
 	       "The first bad commit could be any of:\n");
 	print_commit_list(tried, "%s\n", "%s\n");
 	if (bad)
-		printf("%s\n", sha1_to_hex(bad));
+		printf("%s\n", oid_to_hex(bad));
 	printf("We cannot bisect more!\n");
 	exit(2);
 }
 
-static int is_expected_rev(const unsigned char *sha1)
+static int is_expected_rev(const struct object_id *oid)
 {
 	const char *filename = git_path("BISECT_EXPECTED_REV");
 	struct stat st;
@@ -658,7 +658,7 @@ static int is_expected_rev(const unsigned char *sha1)
 		return 0;
 
 	if (strbuf_getline(&str, fp, '\n') != EOF)
-		res = !strcmp(str.buf, sha1_to_hex(sha1));
+		res = !strcmp(str.buf, oid_to_hex(oid));
 
 	strbuf_release(&str);
 	fclose(fp);
@@ -719,7 +719,7 @@ static struct commit **get_bad_and_good_commits(int *rev_nr)
 	struct commit **rev = xmalloc(len * sizeof(*rev));
 	int i, n = 0;
 
-	rev[n++] = get_commit_reference(current_bad_sha1);
+	rev[n++] = get_commit_reference(current_bad_oid->hash);
 	for (i = 0; i < good_revs.nr; i++)
 		rev[n++] = get_commit_reference(good_revs.sha1[i]);
 	*rev_nr = n;
@@ -729,8 +729,8 @@ static struct commit **get_bad_and_good_commits(int *rev_nr)
 
 static void handle_bad_merge_base(void)
 {
-	if (is_expected_rev(current_bad_sha1)) {
-		char *bad_hex = sha1_to_hex(current_bad_sha1);
+	if (is_expected_rev(current_bad_oid)) {
+		char *bad_hex = oid_to_hex(current_bad_oid);
 		char *good_hex = join_sha1_array_hex(&good_revs, ' ');
 
 		fprintf(stderr, "The merge base %s is bad.\n"
@@ -750,7 +750,7 @@ static void handle_bad_merge_base(void)
 static void handle_skipped_merge_base(const unsigned char *mb)
 {
 	char *mb_hex = sha1_to_hex(mb);
-	char *bad_hex = sha1_to_hex(current_bad_sha1);
+	char *bad_hex = sha1_to_hex(current_bad_oid->hash);
 	char *good_hex = join_sha1_array_hex(&good_revs, ' ');
 
 	warning("the merge base between %s and [%s] "
@@ -781,7 +781,7 @@ static void check_merge_bases(int no_checkout)
 
 	for (; result; result = result->next) {
 		const unsigned char *mb = result->item->object.sha1;
-		if (!hashcmp(mb, current_bad_sha1)) {
+		if (!hashcmp(mb, current_bad_oid->hash)) {
 			handle_bad_merge_base();
 		} else if (0 <= sha1_array_lookup(&good_revs, mb)) {
 			continue;
@@ -838,7 +838,7 @@ static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout)
 	struct stat st;
 	int fd;
 
-	if (!current_bad_sha1)
+	if (!current_bad_oid)
 		die("a bad revision is needed");
 
 	/* Check if file BISECT_ANCESTORS_OK exists. */
@@ -903,7 +903,7 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	struct commit_list *tried;
 	int reaches = 0, all = 0, nr, steps;
 	const unsigned char *bisect_rev;
-	char bisect_rev_hex[41];
+	char bisect_rev_hex[GIT_SHA1_HEXSZ + 1];
 
 	if (read_bisect_refs())
 		die("reading bisect refs failed");
@@ -927,7 +927,7 @@ int bisect_next_all(const char *prefix, int no_checkout)
 		exit_if_skipped_commits(tried, NULL);
 
 		printf("%s was both good and bad\n",
-		       sha1_to_hex(current_bad_sha1));
+		       oid_to_hex(current_bad_oid));
 		exit(1);
 	}
 
@@ -938,10 +938,10 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	}
 
 	bisect_rev = revs.commits->item->object.sha1;
-	memcpy(bisect_rev_hex, sha1_to_hex(bisect_rev), 41);
+	memcpy(bisect_rev_hex, sha1_to_hex(bisect_rev), GIT_SHA1_HEXSZ + 1);
 
-	if (!hashcmp(bisect_rev, current_bad_sha1)) {
-		exit_if_skipped_commits(tried, current_bad_sha1);
+	if (!hashcmp(bisect_rev, current_bad_oid->hash)) {
+		exit_if_skipped_commits(tried, current_bad_oid);
 		printf("%s is the first bad commit\n", bisect_rev_hex);
 		show_diff_tree(prefix, revs.commits->item);
 		/* This means the bisection process succeeded. */
diff --git a/builtin/add.c b/builtin/add.c
index 3390933d68..df5135bf62 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -63,6 +63,7 @@ static void update_callback(struct diff_queue_struct *q,
 		switch (fix_unmerged_status(p, data)) {
 		default:
 			die(_("unexpected diff status %c"), p->status);
+		case DIFF_STATUS_ADDED:
 		case DIFF_STATUS_MODIFIED:
 		case DIFF_STATUS_TYPE_CHANGED:
 			if (add_file_to_index(&the_index, path, data->flags)) {
@@ -208,7 +209,8 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	if (run_diff_files(&rev, 0))
 		die(_("Could not write patch"));
 
-	launch_editor(file, NULL, NULL);
+	if (launch_editor(file, NULL, NULL))
+		die(_("editing patch failed"));
 
 	if (stat(file, &st))
 		die_errno(_("Could not stat '%s'"), file);
diff --git a/builtin/apply.c b/builtin/apply.c
index 0769b09287..146be97a1a 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -208,7 +208,7 @@ struct patch {
 	struct patch *next;
 
 	/* three-way fallback result */
-	unsigned char threeway_stage[3][20];
+	struct object_id threeway_stage[3];
 };
 
 static void free_fragment_list(struct fragment *list)
@@ -3426,11 +3426,11 @@ static int try_threeway(struct image *image, struct patch *patch,
 	if (status) {
 		patch->conflicted_threeway = 1;
 		if (patch->is_new)
-			hashclr(patch->threeway_stage[0]);
+			oidclr(&patch->threeway_stage[0]);
 		else
-			hashcpy(patch->threeway_stage[0], pre_sha1);
-		hashcpy(patch->threeway_stage[1], our_sha1);
-		hashcpy(patch->threeway_stage[2], post_sha1);
+			hashcpy(patch->threeway_stage[0].hash, pre_sha1);
+		hashcpy(patch->threeway_stage[1].hash, our_sha1);
+		hashcpy(patch->threeway_stage[2].hash, post_sha1);
 		fprintf(stderr, "Applied patch to '%s' with conflicts.\n", patch->new_name);
 	} else {
 		fprintf(stderr, "Applied patch to '%s' cleanly.\n", patch->new_name);
@@ -4186,14 +4186,14 @@ static void add_conflicted_stages_file(struct patch *patch)
 
 	remove_file_from_cache(patch->new_name);
 	for (stage = 1; stage < 4; stage++) {
-		if (is_null_sha1(patch->threeway_stage[stage - 1]))
+		if (is_null_oid(&patch->threeway_stage[stage - 1]))
 			continue;
 		ce = xcalloc(1, ce_size);
 		memcpy(ce->name, patch->new_name, namelen);
 		ce->ce_mode = create_ce_mode(mode);
 		ce->ce_flags = create_ce_flags(stage);
 		ce->ce_namelen = namelen;
-		hashcpy(ce->sha1, patch->threeway_stage[stage - 1]);
+		hashcpy(ce->sha1, patch->threeway_stage[stage - 1].hash);
 		if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
 			die(_("unable to add cache entry for %s"), patch->new_name);
 	}
diff --git a/builtin/blame.c b/builtin/blame.c
index 06484c2e0e..b3e948e757 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -26,8 +26,9 @@
 #include "userdiff.h"
 #include "line-range.h"
 #include "line-log.h"
+#include "dir.h"
 
-static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] file");
+static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");
 
 static const char *blame_opt_usage[] = {
 	blame_usage,
@@ -2151,16 +2152,6 @@ static void sanity_check_refcnt(struct scoreboard *sb)
 	}
 }
 
-/*
- * Used for the command line parsing; check if the path exists
- * in the working tree.
- */
-static int has_string_in_work_tree(const char *path)
-{
-	struct stat st;
-	return !lstat(path, &st);
-}
-
 static unsigned parse_score(const char *arg)
 {
 	char *end;
@@ -2348,6 +2339,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 		if (strbuf_read(&buf, 0, 0) < 0)
 			die_errno("failed to read from stdin");
 	}
+	convert_to_git(path, buf.buf, buf.len, &buf, 0);
 	origin->file.ptr = buf.buf;
 	origin->file.size = buf.len;
 	pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
@@ -2655,14 +2647,14 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		if (argc < 2)
 			usage_with_options(blame_opt_usage, options);
 		path = add_prefix(prefix, argv[argc - 1]);
-		if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
+		if (argc == 3 && !file_exists(path)) { /* (2b) */
 			path = add_prefix(prefix, argv[1]);
 			argv[1] = argv[2];
 		}
 		argv[argc - 1] = "--";
 
 		setup_work_tree();
-		if (!has_string_in_work_tree(path))
+		if (!file_exists(path))
 			die_errno("cannot stat path '%s'", path);
 	}
 
diff --git a/builtin/branch.c b/builtin/branch.c
index 1d150378e9..9cbab189f5 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -242,7 +242,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 					    sha1, &flags);
 		if (!target) {
 			error(remote_branch
-			      ? _("remote branch '%s' not found.")
+			      ? _("remote-tracking branch '%s' not found.")
 			      : _("branch '%s' not found."), bname.buf);
 			ret = 1;
 			continue;
@@ -257,7 +257,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 
 		if (delete_ref(name, sha1, REF_NODEREF)) {
 			error(remote_branch
-			      ? _("Error deleting remote branch '%s'")
+			      ? _("Error deleting remote-tracking branch '%s'")
 			      : _("Error deleting branch '%s'"),
 			      bname.buf);
 			ret = 1;
@@ -265,7 +265,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 		}
 		if (!quiet) {
 			printf(remote_branch
-			       ? _("Deleted remote branch %s (was %s).\n")
+			       ? _("Deleted remote-tracking branch %s (was %s).\n")
 			       : _("Deleted branch %s (was %s).\n"),
 			       bname.buf,
 			       (flags & REF_ISBROKEN) ? "broken"
@@ -771,7 +771,6 @@ static const char edit_description[] = "BRANCH_DESCRIPTION";
 
 static int edit_branch_description(const char *branch_name)
 {
-	FILE *fp;
 	int status;
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf name = STRBUF_INIT;
@@ -784,8 +783,7 @@ static int edit_branch_description(const char *branch_name)
 		    "  %s\n"
 		    "Lines starting with '%c' will be stripped.\n",
 		    branch_name, comment_line_char);
-	fp = fopen(git_path(edit_description), "w");
-	if ((fwrite(buf.buf, 1, buf.len, fp) < buf.len) || fclose(fp)) {
+	if (write_file(git_path(edit_description), 0, "%s", buf.buf)) {
 		strbuf_release(&buf);
 		return error(_("could not write branch description template: %s"),
 			     strerror(errno));
diff --git a/builtin/bundle.c b/builtin/bundle.c
index 92a8a6026a..4883a435a9 100644
--- a/builtin/bundle.c
+++ b/builtin/bundle.c
@@ -42,6 +42,10 @@ int cmd_bundle(int argc, const char **argv, const char *prefix)
 
 	if (!strcmp(cmd, "verify")) {
 		close(bundle_fd);
+		if (argc != 1) {
+			usage(builtin_bundle_usage);
+			return 1;
+		}
 		if (verify_bundle(&header, 1))
 			return 1;
 		fprintf(stderr, _("%s is okay\n"), bundle_file);
@@ -52,6 +56,10 @@ int cmd_bundle(int argc, const char **argv, const char *prefix)
 		return !!list_bundle_refs(&header, argc, argv);
 	}
 	if (!strcmp(cmd, "create")) {
+		if (argc < 2) {
+			usage(builtin_bundle_usage);
+			return 1;
+		}
 		if (!startup_info->have_repository)
 			die(_("Need a repository to create a bundle."));
 		return !!create_bundle(&header, bundle_file, argc, argv);
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index df99df4db1..049a95f1f1 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -8,14 +8,22 @@
 #include "parse-options.h"
 #include "userdiff.h"
 #include "streaming.h"
+#include "tree-walk.h"
 
-static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
+static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
+			int unknown_type)
 {
 	unsigned char sha1[20];
 	enum object_type type;
 	char *buf;
 	unsigned long size;
 	struct object_context obj_context;
+	struct object_info oi = {NULL};
+	struct strbuf sb = STRBUF_INIT;
+	unsigned flags = LOOKUP_REPLACE_OBJECT;
+
+	if (unknown_type)
+		flags |= LOOKUP_UNKNOWN_OBJECT;
 
 	if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
 		die("Not a valid object name %s", obj_name);
@@ -23,20 +31,22 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
 	buf = NULL;
 	switch (opt) {
 	case 't':
-		type = sha1_object_info(sha1, NULL);
-		if (type > 0) {
-			printf("%s\n", typename(type));
+		oi.typename = &sb;
+		if (sha1_object_info_extended(sha1, &oi, flags) < 0)
+			die("git cat-file: could not get object info");
+		if (sb.len) {
+			printf("%s\n", sb.buf);
+			strbuf_release(&sb);
 			return 0;
 		}
 		break;
 
 	case 's':
-		type = sha1_object_info(sha1, &size);
-		if (type > 0) {
-			printf("%lu\n", size);
-			return 0;
-		}
-		break;
+		oi.sizep = &size;
+		if (sha1_object_info_extended(sha1, &oi, flags) < 0)
+			die("git cat-file: could not get object info");
+		printf("%lu\n", size);
+		return 0;
 
 	case 'e':
 		return !has_sha1_file(sha1);
@@ -224,6 +234,7 @@ static void print_object_or_die(int fd, struct expand_data *data)
 
 struct batch_options {
 	int enabled;
+	int follow_symlinks;
 	int print_contents;
 	const char *format;
 };
@@ -232,12 +243,44 @@ static int batch_one_object(const char *obj_name, struct batch_options *opt,
 			    struct expand_data *data)
 {
 	struct strbuf buf = STRBUF_INIT;
+	struct object_context ctx;
+	int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
+	enum follow_symlinks_result result;
 
 	if (!obj_name)
 	   return 1;
 
-	if (get_sha1(obj_name, data->sha1)) {
-		printf("%s missing\n", obj_name);
+	result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
+	if (result != FOUND) {
+		switch (result) {
+		case MISSING_OBJECT:
+			printf("%s missing\n", obj_name);
+			break;
+		case DANGLING_SYMLINK:
+			printf("dangling %"PRIuMAX"\n%s\n",
+			       (uintmax_t)strlen(obj_name), obj_name);
+			break;
+		case SYMLINK_LOOP:
+			printf("loop %"PRIuMAX"\n%s\n",
+			       (uintmax_t)strlen(obj_name), obj_name);
+			break;
+		case NOT_DIR:
+			printf("notdir %"PRIuMAX"\n%s\n",
+			       (uintmax_t)strlen(obj_name), obj_name);
+			break;
+		default:
+			die("BUG: unknown get_sha1_with_context result %d\n",
+			       result);
+			break;
+		}
+		fflush(stdout);
+		return 0;
+	}
+
+	if (ctx.mode == 0) {
+		printf("symlink %"PRIuMAX"\n%s\n",
+		       (uintmax_t)ctx.symlink_path.len,
+		       ctx.symlink_path.buf);
 		fflush(stdout);
 		return 0;
 	}
@@ -323,8 +366,8 @@ static int batch_objects(struct batch_options *opt)
 }
 
 static const char * const cat_file_usage[] = {
-	N_("git cat-file (-t | -s | -e | -p | <type> | --textconv) <object>"),
-	N_("git cat-file (--batch | --batch-check) < <list-of-objects>"),
+	N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
+	N_("git cat-file (--batch | --batch-check) [--follow-symlinks] < <list-of-objects>"),
 	NULL
 };
 
@@ -342,9 +385,8 @@ static int batch_option_callback(const struct option *opt,
 {
 	struct batch_options *bo = opt->value;
 
-	if (unset) {
-		memset(bo, 0, sizeof(*bo));
-		return 0;
+	if (bo->enabled) {
+		return 1;
 	}
 
 	bo->enabled = 1;
@@ -359,30 +401,32 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 	int opt = 0;
 	const char *exp_type = NULL, *obj_name = NULL;
 	struct batch_options batch = {0};
+	int unknown_type = 0;
 
 	const struct option options[] = {
 		OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
-		OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
-		OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
-		OPT_SET_INT('e', NULL, &opt,
+		OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
+		OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
+		OPT_CMDMODE('e', NULL, &opt,
 			    N_("exit with zero when there's no error"), 'e'),
-		OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
-		OPT_SET_INT(0, "textconv", &opt,
+		OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
+		OPT_CMDMODE(0, "textconv", &opt,
 			    N_("for blob objects, run textconv on object's content"), 'c'),
+		OPT_BOOL( 0, "allow-unknown-type", &unknown_type,
+			  N_("allow -s and -t to work with broken/corrupt objects")),
 		{ OPTION_CALLBACK, 0, "batch", &batch, "format",
 			N_("show info and content of objects fed from the standard input"),
 			PARSE_OPT_OPTARG, batch_option_callback },
 		{ OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 			N_("show info about objects fed from the standard input"),
 			PARSE_OPT_OPTARG, batch_option_callback },
+		OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
+			 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 		OPT_END()
 	};
 
 	git_config(git_cat_file_config, NULL);
 
-	if (argc != 3 && argc != 2)
-		usage_with_options(cat_file_usage, options);
-
 	argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 
 	if (opt) {
@@ -402,8 +446,14 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 		usage_with_options(cat_file_usage, options);
 	}
 
+	if (batch.follow_symlinks && !batch.enabled) {
+		usage_with_options(cat_file_usage, options);
+	}
+
 	if (batch.enabled)
 		return batch_objects(&batch);
 
-	return cat_one_file(opt, exp_type, obj_name);
+	if (unknown_type && opt != 't' && opt != 's')
+		die("git cat-file --allow-unknown-type: use with -s or -t");
+	return cat_one_file(opt, exp_type, obj_name, unknown_type);
 }
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index 9ca2da1583..8028c3768f 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -241,7 +241,7 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 	/* Check out named files first */
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
-		const char *p;
+		char *p;
 
 		if (all)
 			die("git checkout-index: don't mix '--all' and explicit filenames");
@@ -249,8 +249,7 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 			die("git checkout-index: don't mix '--stdin' and explicit filenames");
 		p = prefix_path(prefix, prefix_length, arg);
 		checkout_file(p, prefix);
-		if (p < arg || p > arg + strlen(arg))
-			free((char *)p);
+		free(p);
 	}
 
 	if (read_from_stdin) {
@@ -260,7 +259,7 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 			die("git checkout-index: don't mix '--all' and '--stdin'");
 
 		while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
-			const char *p;
+			char *p;
 			if (line_termination && buf.buf[0] == '"') {
 				strbuf_reset(&nbuf);
 				if (unquote_c_style(&nbuf, buf.buf, NULL))
@@ -269,8 +268,7 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 			}
 			p = prefix_path(prefix, prefix_length, buf.buf);
 			checkout_file(p, prefix);
-			if (p < buf.buf || p > buf.buf + buf.len)
-				free((char *)p);
+			free(p);
 		}
 		strbuf_release(&nbuf);
 		strbuf_release(&buf);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 3e141fc149..2f92328db4 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -20,6 +20,7 @@
 #include "resolve-undo.h"
 #include "submodule.h"
 #include "argv-array.h"
+#include "sigchain.h"
 
 static const char * const checkout_usage[] = {
 	N_("git checkout [<options>] <branch>"),
@@ -36,6 +37,7 @@ struct checkout_opts {
 	int writeout_stage;
 	int overwrite_ignore;
 	int ignore_skipworktree;
+	int ignore_other_worktrees;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -48,6 +50,10 @@ struct checkout_opts {
 	const char *prefix;
 	struct pathspec pathspec;
 	struct tree *source_tree;
+
+	const char *new_worktree;
+	const char **saved_argv;
+	int new_worktree_mode;
 };
 
 static int post_checkout_hook(struct commit *old, struct commit *new,
@@ -267,6 +273,9 @@ static int checkout_paths(const struct checkout_opts *opts,
 		die(_("Cannot update paths and switch to branch '%s' at the same time."),
 		    opts->new_branch);
 
+	if (opts->new_worktree)
+		die(_("'%s' cannot be used with updating paths"), "--to");
+
 	if (opts->patch_mode)
 		return run_add_interactive(revision, "--patch=checkout",
 					   &opts->pathspec);
@@ -441,6 +450,11 @@ struct branch_info {
 	const char *name; /* The short name used */
 	const char *path; /* The full name of a real branch */
 	struct commit *commit; /* The named commit */
+	/*
+	 * if not null the branch is detached because it's already
+	 * checked out in this checkout
+	 */
+	char *checkout;
 };
 
 static void setup_branch_path(struct branch_info *branch)
@@ -502,7 +516,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 			topts.dir->flags |= DIR_SHOW_IGNORED;
 			setup_standard_excludes(topts.dir);
 		}
-		tree = parse_tree_indirect(old->commit ?
+		tree = parse_tree_indirect(old->commit && !opts->new_worktree_mode ?
 					   old->commit->object.sha1 :
 					   EMPTY_TREE_SHA1_BIN);
 		init_tree_desc(&trees[0], tree->buffer, tree->size);
@@ -606,18 +620,21 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
 		if (opts->new_orphan_branch) {
 			if (opts->new_branch_log && !log_all_ref_updates) {
 				int temp;
-				char log_file[PATH_MAX];
-				char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+				struct strbuf log_file = STRBUF_INIT;
+				int ret;
+				const char *ref_name;
 
+				ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
 				temp = log_all_ref_updates;
 				log_all_ref_updates = 1;
-				if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
+				ret = log_ref_setup(ref_name, &log_file);
+				log_all_ref_updates = temp;
+				strbuf_release(&log_file);
+				if (ret) {
 					fprintf(stderr, _("Can not do reflog for '%s'\n"),
 					    opts->new_orphan_branch);
-					log_all_ref_updates = temp;
 					return;
 				}
-				log_all_ref_updates = temp;
 			}
 		}
 		else
@@ -743,10 +760,17 @@ static void suggest_reattach(struct commit *commit, struct rev_info *revs)
 
 	if (advice_detached_head)
 		fprintf(stderr,
-			_(
+			Q_(
+			/* The singular version */
+			"If you want to keep it by creating a new branch, "
+			"this may be a good time\nto do so with:\n\n"
+			" git branch <new-branch-name> %s\n\n",
+			/* The plural version */
 			"If you want to keep them by creating a new branch, "
 			"this may be a good time\nto do so with:\n\n"
-			" git branch <new-branch-name> %s\n\n"),
+			" git branch <new-branch-name> %s\n\n",
+			/* Give ngettext() the count */
+			lost),
 			find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 }
 
@@ -815,7 +839,8 @@ static int switch_branches(const struct checkout_opts *opts,
 		return ret;
 	}
 
-	if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
+	if (!opts->quiet && !old.path && old.commit &&
+	    new->commit != old.commit && !opts->new_worktree_mode)
 		orphaned_commit_warning(old.commit, new->commit);
 
 	update_refs_for_switch(opts, &old, new);
@@ -825,6 +850,138 @@ static int switch_branches(const struct checkout_opts *opts,
 	return ret || writeout_error;
 }
 
+static char *junk_work_tree;
+static char *junk_git_dir;
+static int is_junk;
+static pid_t junk_pid;
+
+static void remove_junk(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	if (!is_junk || getpid() != junk_pid)
+		return;
+	if (junk_git_dir) {
+		strbuf_addstr(&sb, junk_git_dir);
+		remove_dir_recursively(&sb, 0);
+		strbuf_reset(&sb);
+	}
+	if (junk_work_tree) {
+		strbuf_addstr(&sb, junk_work_tree);
+		remove_dir_recursively(&sb, 0);
+	}
+	strbuf_release(&sb);
+}
+
+static void remove_junk_on_signal(int signo)
+{
+	remove_junk();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
+static int prepare_linked_checkout(const struct checkout_opts *opts,
+				   struct branch_info *new)
+{
+	struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT;
+	struct strbuf sb = STRBUF_INIT;
+	const char *path = opts->new_worktree, *name;
+	struct stat st;
+	struct child_process cp;
+	int counter = 0, len, ret;
+
+	if (!new->commit)
+		die(_("no branch specified"));
+	if (file_exists(path) && !is_empty_dir(path))
+		die(_("'%s' already exists"), path);
+
+	len = strlen(path);
+	while (len && is_dir_sep(path[len - 1]))
+		len--;
+
+	for (name = path + len - 1; name > path; name--)
+		if (is_dir_sep(*name)) {
+			name++;
+			break;
+		}
+	strbuf_addstr(&sb_repo,
+		      git_path("worktrees/%.*s", (int)(path + len - name), name));
+	len = sb_repo.len;
+	if (safe_create_leading_directories_const(sb_repo.buf))
+		die_errno(_("could not create leading directories of '%s'"),
+			  sb_repo.buf);
+	while (!stat(sb_repo.buf, &st)) {
+		counter++;
+		strbuf_setlen(&sb_repo, len);
+		strbuf_addf(&sb_repo, "%d", counter);
+	}
+	name = strrchr(sb_repo.buf, '/') + 1;
+
+	junk_pid = getpid();
+	atexit(remove_junk);
+	sigchain_push_common(remove_junk_on_signal);
+
+	if (mkdir(sb_repo.buf, 0777))
+		die_errno(_("could not create directory of '%s'"), sb_repo.buf);
+	junk_git_dir = xstrdup(sb_repo.buf);
+	is_junk = 1;
+
+	/*
+	 * lock the incomplete repo so prune won't delete it, unlock
+	 * after the preparation is over.
+	 */
+	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+	write_file(sb.buf, 1, "initializing\n");
+
+	strbuf_addf(&sb_git, "%s/.git", path);
+	if (safe_create_leading_directories_const(sb_git.buf))
+		die_errno(_("could not create leading directories of '%s'"),
+			  sb_git.buf);
+	junk_work_tree = xstrdup(path);
+
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
+	write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
+	write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
+		   real_path(get_git_common_dir()), name);
+	/*
+	 * This is to keep resolve_ref() happy. We need a valid HEAD
+	 * or is_git_directory() will reject the directory. Any valid
+	 * value would do because this value will be ignored and
+	 * replaced at the next (real) checkout.
+	 */
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
+	write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1));
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
+	write_file(sb.buf, 1, "../..\n");
+
+	if (!opts->quiet)
+		fprintf_ln(stderr, _("Enter %s (identifier %s)"), path, name);
+
+	setenv("GIT_CHECKOUT_NEW_WORKTREE", "1", 1);
+	setenv(GIT_DIR_ENVIRONMENT, sb_git.buf, 1);
+	setenv(GIT_WORK_TREE_ENVIRONMENT, path, 1);
+	memset(&cp, 0, sizeof(cp));
+	cp.git_cmd = 1;
+	cp.argv = opts->saved_argv;
+	ret = run_command(&cp);
+	if (!ret) {
+		is_junk = 0;
+		free(junk_work_tree);
+		free(junk_git_dir);
+		junk_work_tree = NULL;
+		junk_git_dir = NULL;
+	}
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+	unlink_or_warn(sb.buf);
+	strbuf_release(&sb);
+	strbuf_release(&sb_repo);
+	strbuf_release(&sb_git);
+	return ret;
+}
+
 static int git_checkout_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "diff.ignoresubmodules")) {
@@ -880,13 +1037,80 @@ static const char *unique_tracking_name(const char *name, unsigned char *sha1)
 	return NULL;
 }
 
+static void check_linked_checkout(struct branch_info *new, const char *id)
+{
+	struct strbuf sb = STRBUF_INIT;
+	struct strbuf path = STRBUF_INIT;
+	struct strbuf gitdir = STRBUF_INIT;
+	const char *start, *end;
+
+	if (id)
+		strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+	else
+		strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+
+	if (strbuf_read_file(&sb, path.buf, 0) < 0 ||
+	    !skip_prefix(sb.buf, "ref:", &start))
+		goto done;
+	while (isspace(*start))
+		start++;
+	end = start;
+	while (*end && !isspace(*end))
+		end++;
+	if (strncmp(start, new->path, end - start) || new->path[end - start] != '\0')
+		goto done;
+	if (id) {
+		strbuf_reset(&path);
+		strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
+		if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
+			goto done;
+		strbuf_rtrim(&gitdir);
+	} else
+		strbuf_addstr(&gitdir, get_git_common_dir());
+	die(_("'%s' is already checked out at '%s'"), new->name, gitdir.buf);
+done:
+	strbuf_release(&path);
+	strbuf_release(&sb);
+	strbuf_release(&gitdir);
+}
+
+static void check_linked_checkouts(struct branch_info *new)
+{
+	struct strbuf path = STRBUF_INIT;
+	DIR *dir;
+	struct dirent *d;
+
+	strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+	if ((dir = opendir(path.buf)) == NULL) {
+		strbuf_release(&path);
+		return;
+	}
+
+	/*
+	 * $GIT_COMMON_DIR/HEAD is practically outside
+	 * $GIT_DIR so resolve_ref_unsafe() won't work (it
+	 * uses git_path). Parse the ref ourselves.
+	 */
+	check_linked_checkout(new, NULL);
+
+	while ((d = readdir(dir)) != NULL) {
+		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+			continue;
+		check_linked_checkout(new, d->d_name);
+	}
+	strbuf_release(&path);
+	closedir(dir);
+}
+
 static int parse_branchname_arg(int argc, const char **argv,
 				int dwim_new_local_branch_ok,
 				struct branch_info *new,
-				struct tree **source_tree,
-				unsigned char rev[20],
-				const char **new_branch)
+				struct checkout_opts *opts,
+				unsigned char rev[20])
 {
+	struct tree **source_tree = &opts->source_tree;
+	const char **new_branch = &opts->new_branch;
+	int force_detach = opts->force_detach;
 	int argcount = 0;
 	unsigned char branch_rev[20];
 	const char *arg;
@@ -1007,6 +1231,17 @@ static int parse_branchname_arg(int argc, const char **argv,
 	else
 		new->path = NULL; /* not an existing branch */
 
+	if (new->path && !force_detach && !*new_branch) {
+		unsigned char sha1[20];
+		int flag;
+		char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
+		if (head_ref &&
+		    (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)) &&
+		    !opts->ignore_other_worktrees)
+			check_linked_checkouts(new);
+		free(head_ref);
+	}
+
 	new->commit = lookup_commit_reference_gently(rev, 1);
 	if (!new->commit) {
 		/* not a commit */
@@ -1086,6 +1321,9 @@ static int checkout_branch(struct checkout_opts *opts,
 		die(_("Cannot switch branch to a non-commit '%s'"),
 		    new->name);
 
+	if (opts->new_worktree)
+		return prepare_linked_checkout(opts, new);
+
 	if (!new->commit && opts->new_branch) {
 		unsigned char rev[20];
 		int flag;
@@ -1128,6 +1366,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			 N_("do not limit pathspecs to sparse entries only")),
 		OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
 				N_("second guess 'git checkout <no-such-branch>'")),
+		OPT_FILENAME(0, "to", &opts.new_worktree,
+			   N_("check a branch out in a separate working directory")),
+		OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
+			 N_("do not check if another worktree is holding the given ref")),
 		OPT_END(),
 	};
 
@@ -1136,6 +1378,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.overwrite_ignore = 1;
 	opts.prefix = prefix;
 
+	opts.saved_argv = xmalloc(sizeof(const char *) * (argc + 2));
+	memcpy(opts.saved_argv, argv, sizeof(const char *) * (argc + 1));
+
 	gitmodules_config();
 	git_config(git_checkout_config, &opts);
 
@@ -1144,6 +1389,14 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
+	/* recursive execution from checkout_new_worktree() */
+	opts.new_worktree_mode = getenv("GIT_CHECKOUT_NEW_WORKTREE") != NULL;
+	if (opts.new_worktree_mode)
+		opts.new_worktree = NULL;
+
+	if (!opts.new_worktree)
+		setup_work_tree();
+
 	if (conflict_style) {
 		opts.merge = 1; /* implied */
 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
@@ -1197,8 +1450,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			opts.track == BRANCH_TRACK_UNSPECIFIED &&
 			!opts.new_branch;
 		int n = parse_branchname_arg(argc, argv, dwim_ok,
-					     &new, &opts.source_tree,
-					     rev, &opts.new_branch);
+					     &new, &opts, rev);
 		argv += n;
 		argc -= n;
 	}
diff --git a/builtin/clean.c b/builtin/clean.c
index 98c103fa8b..6dcb72e644 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -314,7 +314,6 @@ static void print_highlight_menu_stuff(struct menu_stuff *stuff, int **chosen)
 {
 	struct string_list menu_list = STRING_LIST_INIT_DUP;
 	struct strbuf menu = STRBUF_INIT;
-	struct strbuf buf = STRBUF_INIT;
 	struct menu_item *menu_item;
 	struct string_list_item *string_list_item;
 	int i;
@@ -363,7 +362,6 @@ static void print_highlight_menu_stuff(struct menu_stuff *stuff, int **chosen)
 	pretty_print_menus(&menu_list);
 
 	strbuf_release(&menu);
-	strbuf_release(&buf);
 	string_list_clear(&menu_list, 0);
 }
 
@@ -941,15 +939,15 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 		if (!cache_name_is_other(ent->name, ent->len))
 			continue;
 
-		if (lstat(ent->name, &st))
-			die_errno("Cannot lstat '%s'", ent->name);
-
 		if (pathspec.nr)
 			matches = dir_path_match(ent, &pathspec, 0, NULL);
 
 		if (pathspec.nr && !matches)
 			continue;
 
+		if (lstat(ent->name, &st))
+			die_errno("Cannot lstat '%s'", ent->name);
+
 		if (S_ISDIR(st.st_mode) && !remove_directories &&
 		    matches != MATCHED_EXACTLY)
 			continue;
diff --git a/builtin/clone.c b/builtin/clone.c
index 53a2e5af35..b878252bc2 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -293,16 +293,17 @@ static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 	struct strbuf line = STRBUF_INIT;
 
 	while (strbuf_getline(&line, in, '\n') != EOF) {
-		char *abs_path, abs_buf[PATH_MAX];
+		char *abs_path;
 		if (!line.len || line.buf[0] == '#')
 			continue;
 		if (is_absolute_path(line.buf)) {
 			add_to_alternates_file(line.buf);
 			continue;
 		}
-		abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
-		normalize_path_copy(abs_buf, abs_path);
-		add_to_alternates_file(abs_buf);
+		abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
+		normalize_path_copy(abs_path, abs_path);
+		add_to_alternates_file(abs_path);
+		free(abs_path);
 	}
 	strbuf_release(&line);
 	fclose(in);
@@ -906,6 +907,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	remote = remote_get(option_origin);
 	transport = transport_get(remote, remote->url[0]);
+	transport_set_verbosity(transport, option_verbosity, option_progress);
+
 	path = get_repo_path(remote->url[0], &is_bundle);
 	is_local = option_local != 0 && path && !is_bundle;
 	if (is_local) {
@@ -932,8 +935,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (option_single_branch)
 		transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
 
-	transport_set_verbosity(transport, option_verbosity, option_progress);
-
 	if (option_upload_pack)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 				     option_upload_pack);
diff --git a/builtin/commit.c b/builtin/commit.c
index da79ac4bc7..254477fd1d 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -170,7 +170,7 @@ static void determine_whence(struct wt_status *s)
 		whence = FROM_MERGE;
 	else if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
 		whence = FROM_CHERRY_PICK;
-		if (file_exists(git_path("sequencer")))
+		if (file_exists(git_path(SEQ_DIR)))
 			sequencer_in_use = 1;
 	}
 	else
@@ -1366,13 +1366,14 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, &s.pathspec, NULL, NULL);
 
 	fd = hold_locked_index(&index_lock, 0);
-	if (0 <= fd)
-		update_index_if_able(&the_index, &index_lock);
 
 	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
 	s.ignore_submodule_arg = ignore_submodule_arg;
 	wt_status_collect(&s);
 
+	if (0 <= fd)
+		update_index_if_able(&the_index, &index_lock);
+
 	if (s.relative_paths)
 		s.prefix = prefix;
 
@@ -1398,12 +1399,10 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 
 static const char *implicit_ident_advice(void)
 {
-	char *user_config = NULL;
-	char *xdg_config = NULL;
-	int config_exists;
+	char *user_config = expand_user_path("~/.gitconfig");
+	char *xdg_config = xdg_config_home("config");
+	int config_exists = file_exists(user_config) || file_exists(xdg_config);
 
-	home_config_paths(&user_config, &xdg_config, "config");
-	config_exists = file_exists(user_config) || file_exists(xdg_config);
 	free(user_config);
 	free(xdg_config);
 
diff --git a/builtin/config.c b/builtin/config.c
index d32c5327e5..7188405f7e 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -193,7 +193,7 @@ static int get_value(const char *key_, const char *regex_)
 
 		key_regexp = (regex_t*)xmalloc(sizeof(regex_t));
 		if (regcomp(key_regexp, key, REG_EXTENDED)) {
-			fprintf(stderr, "Invalid key pattern: %s\n", key_);
+			error("invalid key pattern: %s", key_);
 			free(key_regexp);
 			key_regexp = NULL;
 			ret = CONFIG_INVALID_PATTERN;
@@ -214,7 +214,7 @@ static int get_value(const char *key_, const char *regex_)
 
 		regexp = (regex_t*)xmalloc(sizeof(regex_t));
 		if (regcomp(regexp, regex_, REG_EXTENDED)) {
-			fprintf(stderr, "Invalid pattern: %s\n", regex_);
+			error("invalid pattern: %s", regex_);
 			free(regexp);
 			regexp = NULL;
 			ret = CONFIG_INVALID_PATTERN;
@@ -455,9 +455,9 @@ static char *default_user_config(void)
 	struct strbuf buf = STRBUF_INIT;
 	strbuf_addf(&buf,
 		    _("# This is Git's per-user configuration file.\n"
-		      "[core]\n"
+		      "[user]\n"
 		      "# Please adapt and uncomment the following lines:\n"
-		      "#	user = %s\n"
+		      "#	name = %s\n"
 		      "#	email = %s\n"),
 		    ident_default_name(),
 		    ident_default_email());
@@ -488,10 +488,8 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 
 	if (use_global_config) {
-		char *user_config = NULL;
-		char *xdg_config = NULL;
-
-		home_config_paths(&user_config, &xdg_config, "config");
+		char *user_config = expand_user_path("~/.gitconfig");
+		char *xdg_config = xdg_config_home("config");
 
 		if (!user_config)
 			/*
diff --git a/builtin/count-objects.c b/builtin/count-objects.c
index e47ef0b1af..ad0c79954a 100644
--- a/builtin/count-objects.c
+++ b/builtin/count-objects.c
@@ -70,8 +70,10 @@ int cmd_count_objects(int argc, const char **argv, const char *prefix)
 	/* we do not take arguments other than flags for now */
 	if (argc)
 		usage_with_options(count_objects_usage, opts);
-	if (verbose)
+	if (verbose) {
 		report_garbage = real_report_garbage;
+		report_linked_checkout_garbage();
+	}
 
 	for_each_loose_file_in_objdir(get_object_directory(),
 				      count_loose, count_cruft, NULL, NULL);
diff --git a/builtin/fetch.c b/builtin/fetch.c
index f9512652cf..7910419c93 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -588,7 +588,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 	struct strbuf note = STRBUF_INIT;
 	const char *what, *kind;
 	struct ref *rm;
-	char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
+	char *url;
+	const char *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
 	int want_status;
 
 	fp = fopen(filename, "a");
@@ -822,7 +823,7 @@ static void check_not_current_branch(struct ref *ref_map)
 
 static int truncate_fetch_head(void)
 {
-	char *filename = git_path("FETCH_HEAD");
+	const char *filename = git_path("FETCH_HEAD");
 	FILE *fp = fopen(filename, "w");
 
 	if (!fp)
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 1d962dc569..05f4c26311 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -223,16 +223,14 @@ static void add_branch_desc(struct strbuf *out, const char *name)
 
 #define util_as_integral(elem) ((intptr_t)((elem)->util))
 
-static void record_person(int which, struct string_list *people,
-			  struct commit *commit)
+static void record_person_from_buf(int which, struct string_list *people,
+				   const char *buffer)
 {
-	const char *buffer;
 	char *name_buf, *name, *name_end;
 	struct string_list_item *elem;
 	const char *field;
 
 	field = (which == 'a') ? "\nauthor " : "\ncommitter ";
-	buffer = get_commit_buffer(commit, NULL);
 	name = strstr(buffer, field);
 	if (!name)
 		return;
@@ -245,7 +243,6 @@ static void record_person(int which, struct string_list *people,
 	if (name_end < name)
 		return;
 	name_buf = xmemdupz(name, name_end - name + 1);
-	unuse_commit_buffer(commit, buffer);
 
 	elem = string_list_lookup(people, name_buf);
 	if (!elem) {
@@ -256,6 +253,15 @@ static void record_person(int which, struct string_list *people,
 	free(name_buf);
 }
 
+
+static void record_person(int which, struct string_list *people,
+			  struct commit *commit)
+{
+	const char *buffer = get_commit_buffer(commit, NULL);
+	record_person_from_buf(which, people, buffer);
+	unuse_commit_buffer(commit, buffer);
+}
+
 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
 {
 	const struct string_list_item *a = a_, *b = b_;
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 0c757862e8..4783896fd6 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -225,12 +225,12 @@ static void check_unreachable_object(struct object *obj)
 			printf("dangling %s %s\n", typename(obj->type),
 			       sha1_to_hex(obj->sha1));
 		if (write_lost_and_found) {
-			char *filename = git_path("lost-found/%s/%s",
+			const char *filename = git_path("lost-found/%s/%s",
 				obj->type == OBJ_COMMIT ? "commit" : "other",
 				sha1_to_hex(obj->sha1));
 			FILE *f;
 
-			if (safe_create_leading_directories(filename)) {
+			if (safe_create_leading_directories_const(filename)) {
 				error("Could not create lost-found");
 				return;
 			}
diff --git a/builtin/gc.c b/builtin/gc.c
index 5c634afc00..36fe33300f 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -33,11 +33,13 @@ static int gc_auto_threshold = 6700;
 static int gc_auto_pack_limit = 50;
 static int detach_auto = 1;
 static const char *prune_expire = "2.weeks.ago";
+static const char *prune_worktrees_expire = "3.months.ago";
 
 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
 static struct argv_array reflog = ARGV_ARRAY_INIT;
 static struct argv_array repack = ARGV_ARRAY_INIT;
 static struct argv_array prune = ARGV_ARRAY_INIT;
+static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
 static struct argv_array rerere = ARGV_ARRAY_INIT;
 
 static char *pidfile;
@@ -55,6 +57,17 @@ static void remove_pidfile_on_signal(int signo)
 	raise(signo);
 }
 
+static void git_config_date_string(const char *key, const char **output)
+{
+	if (git_config_get_string_const(key, output))
+		return;
+	if (strcmp(*output, "now")) {
+		unsigned long now = approxidate("now");
+		if (approxidate(*output) >= now)
+			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
+	}
+}
+
 static void gc_config(void)
 {
 	const char *value;
@@ -71,16 +84,8 @@ static void gc_config(void)
 	git_config_get_int("gc.auto", &gc_auto_threshold);
 	git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
 	git_config_get_bool("gc.autodetach", &detach_auto);
-
-	if (!git_config_get_string_const("gc.pruneexpire", &prune_expire)) {
-		if (strcmp(prune_expire, "now")) {
-			unsigned long now = approxidate("now");
-			if (approxidate(prune_expire) >= now) {
-				git_die_config("gc.pruneexpire", _("Invalid gc.pruneexpire: '%s'"),
-						prune_expire);
-			}
-		}
-	}
+	git_config_date_string("gc.pruneexpire", &prune_expire);
+	git_config_date_string("gc.pruneworktreesexpire", &prune_worktrees_expire);
 	git_config(git_default_config, NULL);
 }
 
@@ -287,7 +292,8 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 	argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
 	argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
 	argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
-	argv_array_pushl(&prune, "prune", "--expire", NULL );
+	argv_array_pushl(&prune, "prune", "--expire", NULL);
+	argv_array_pushl(&prune_worktrees, "prune", "--worktrees", "--expire", NULL);
 	argv_array_pushl(&rerere, "rerere", "gc", NULL);
 
 	gc_config();
@@ -357,6 +363,12 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			return error(FAILED_RUN, prune.argv[0]);
 	}
 
+	if (prune_worktrees_expire) {
+		argv_array_push(&prune_worktrees, prune_worktrees_expire);
+		if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
+			return error(FAILED_RUN, prune_worktrees.argv[0]);
+	}
+
 	if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
 		return error(FAILED_RUN, rerere.argv[0]);
 
diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index 207b90c7b1..07fef3cc6b 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -22,10 +22,8 @@ static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigne
 
 	if (strbuf_read(&buf, fd, 4096) < 0)
 		ret = -1;
-	else if (flags & HASH_WRITE_OBJECT)
-		ret = write_sha1_file(buf.buf, buf.len, type, sha1);
 	else
-		ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
+		ret = hash_sha1_file_literally(buf.buf, buf.len, type, sha1, flags);
 	strbuf_release(&buf);
 	return ret;
 }
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index cf654df09b..7ea2020d82 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -18,16 +18,14 @@ static const char index_pack_usage[] =
 struct object_entry {
 	struct pack_idx_entry idx;
 	unsigned long size;
-	unsigned int hdr_size;
-	enum object_type type;
-	enum object_type real_type;
-	unsigned delta_depth;
-	int base_object_no;
+	unsigned char hdr_size;
+	signed char type;
+	signed char real_type;
 };
 
-union delta_base {
-	unsigned char sha1[20];
-	off_t offset;
+struct object_stat {
+	unsigned delta_depth;
+	int base_object_no;
 };
 
 struct base_data {
@@ -49,25 +47,28 @@ struct thread_local {
 	int pack_fd;
 };
 
-/*
- * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
- * to memcmp() only the first 20 bytes.
- */
-#define UNION_BASE_SZ	20
-
 #define FLAG_LINK (1u<<20)
 #define FLAG_CHECKED (1u<<21)
 
-struct delta_entry {
-	union delta_base base;
+struct ofs_delta_entry {
+	off_t offset;
+	int obj_no;
+};
+
+struct ref_delta_entry {
+	unsigned char sha1[20];
 	int obj_no;
 };
 
 static struct object_entry *objects;
-static struct delta_entry *deltas;
+static struct object_stat *obj_stat;
+static struct ofs_delta_entry *ofs_deltas;
+static struct ref_delta_entry *ref_deltas;
 static struct thread_local nothread_data;
 static int nr_objects;
-static int nr_deltas;
+static int nr_ofs_deltas;
+static int nr_ref_deltas;
+static int ref_deltas_alloc;
 static int nr_resolved_deltas;
 static int nr_threads;
 
@@ -476,7 +477,8 @@ static void *unpack_entry_data(unsigned long offset, unsigned long size,
 }
 
 static void *unpack_raw_entry(struct object_entry *obj,
-			      union delta_base *delta_base,
+			      off_t *ofs_offset,
+			      unsigned char *ref_sha1,
 			      unsigned char *sha1)
 {
 	unsigned char *p;
@@ -505,11 +507,10 @@ static void *unpack_raw_entry(struct object_entry *obj,
 
 	switch (obj->type) {
 	case OBJ_REF_DELTA:
-		hashcpy(delta_base->sha1, fill(20));
+		hashcpy(ref_sha1, fill(20));
 		use(20);
 		break;
 	case OBJ_OFS_DELTA:
-		memset(delta_base, 0, sizeof(*delta_base));
 		p = fill(1);
 		c = *p;
 		use(1);
@@ -523,8 +524,8 @@ static void *unpack_raw_entry(struct object_entry *obj,
 			use(1);
 			base_offset = (base_offset << 7) + (c & 127);
 		}
-		delta_base->offset = obj->idx.offset - base_offset;
-		if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
+		*ofs_offset = obj->idx.offset - base_offset;
+		if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 			bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 		break;
 	case OBJ_COMMIT:
@@ -608,55 +609,108 @@ static void *get_data_from_pack(struct object_entry *obj)
 	return unpack_data(obj, NULL, NULL);
 }
 
-static int compare_delta_bases(const union delta_base *base1,
-			       const union delta_base *base2,
-			       enum object_type type1,
-			       enum object_type type2)
+static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
+				   enum object_type type1,
+				   enum object_type type2)
 {
 	int cmp = type1 - type2;
 	if (cmp)
 		return cmp;
-	return memcmp(base1, base2, UNION_BASE_SZ);
+	return offset1 - offset2;
 }
 
-static int find_delta(const union delta_base *base, enum object_type type)
+static int find_ofs_delta(const off_t offset, enum object_type type)
 {
-	int first = 0, last = nr_deltas;
-
-        while (first < last) {
-                int next = (first + last) / 2;
-                struct delta_entry *delta = &deltas[next];
-                int cmp;
-
-		cmp = compare_delta_bases(base, &delta->base,
-					  type, objects[delta->obj_no].type);
-                if (!cmp)
-                        return next;
-                if (cmp < 0) {
-                        last = next;
-                        continue;
-                }
-                first = next+1;
-        }
-        return -first-1;
+	int first = 0, last = nr_ofs_deltas;
+
+	while (first < last) {
+		int next = (first + last) / 2;
+		struct ofs_delta_entry *delta = &ofs_deltas[next];
+		int cmp;
+
+		cmp = compare_ofs_delta_bases(offset, delta->offset,
+					      type, objects[delta->obj_no].type);
+		if (!cmp)
+			return next;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+	return -first-1;
 }
 
-static void find_delta_children(const union delta_base *base,
-				int *first_index, int *last_index,
-				enum object_type type)
+static void find_ofs_delta_children(off_t offset,
+				    int *first_index, int *last_index,
+				    enum object_type type)
 {
-	int first = find_delta(base, type);
+	int first = find_ofs_delta(offset, type);
 	int last = first;
-	int end = nr_deltas - 1;
+	int end = nr_ofs_deltas - 1;
 
 	if (first < 0) {
 		*first_index = 0;
 		*last_index = -1;
 		return;
 	}
-	while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
+	while (first > 0 && ofs_deltas[first - 1].offset == offset)
 		--first;
-	while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
+	while (last < end && ofs_deltas[last + 1].offset == offset)
+		++last;
+	*first_index = first;
+	*last_index = last;
+}
+
+static int compare_ref_delta_bases(const unsigned char *sha1,
+				   const unsigned char *sha2,
+				   enum object_type type1,
+				   enum object_type type2)
+{
+	int cmp = type1 - type2;
+	if (cmp)
+		return cmp;
+	return hashcmp(sha1, sha2);
+}
+
+static int find_ref_delta(const unsigned char *sha1, enum object_type type)
+{
+	int first = 0, last = nr_ref_deltas;
+
+	while (first < last) {
+		int next = (first + last) / 2;
+		struct ref_delta_entry *delta = &ref_deltas[next];
+		int cmp;
+
+		cmp = compare_ref_delta_bases(sha1, delta->sha1,
+					      type, objects[delta->obj_no].type);
+		if (!cmp)
+			return next;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+	return -first-1;
+}
+
+static void find_ref_delta_children(const unsigned char *sha1,
+				    int *first_index, int *last_index,
+				    enum object_type type)
+{
+	int first = find_ref_delta(sha1, type);
+	int last = first;
+	int end = nr_ref_deltas - 1;
+
+	if (first < 0) {
+		*first_index = 0;
+		*last_index = -1;
+		return;
+	}
+	while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
+		--first;
+	while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 		++last;
 	*first_index = first;
 	*last_index = last;
@@ -873,13 +927,15 @@ static void resolve_delta(struct object_entry *delta_obj,
 	void *base_data, *delta_data;
 
 	if (show_stat) {
-		delta_obj->delta_depth = base->obj->delta_depth + 1;
+		int i = delta_obj - objects;
+		int j = base->obj - objects;
+		obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 		deepest_delta_lock();
-		if (deepest_delta < delta_obj->delta_depth)
-			deepest_delta = delta_obj->delta_depth;
+		if (deepest_delta < obj_stat[i].delta_depth)
+			deepest_delta = obj_stat[i].delta_depth;
 		deepest_delta_unlock();
+		obj_stat[i].base_object_no = j;
 	}
-	delta_obj->base_object_no = base->obj - objects;
 	delta_data = get_data_from_pack(delta_obj);
 	base_data = get_base_data(base);
 	result->obj = delta_obj;
@@ -902,7 +958,7 @@ static void resolve_delta(struct object_entry *delta_obj,
  * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
  * and return false.
  */
-static int compare_and_swap_type(enum object_type *type,
+static int compare_and_swap_type(signed char *type,
 				 enum object_type want,
 				 enum object_type set)
 {
@@ -921,16 +977,13 @@ static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 						  struct base_data *prev_base)
 {
 	if (base->ref_last == -1 && base->ofs_last == -1) {
-		union delta_base base_spec;
+		find_ref_delta_children(base->obj->idx.sha1,
+					&base->ref_first, &base->ref_last,
+					OBJ_REF_DELTA);
 
-		hashcpy(base_spec.sha1, base->obj->idx.sha1);
-		find_delta_children(&base_spec,
-				    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
-
-		memset(&base_spec, 0, sizeof(base_spec));
-		base_spec.offset = base->obj->idx.offset;
-		find_delta_children(&base_spec,
-				    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
+		find_ofs_delta_children(base->obj->idx.offset,
+					&base->ofs_first, &base->ofs_last,
+					OBJ_OFS_DELTA);
 
 		if (base->ref_last == -1 && base->ofs_last == -1) {
 			free(base->data);
@@ -941,7 +994,7 @@ static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 	}
 
 	if (base->ref_first <= base->ref_last) {
-		struct object_entry *child = objects + deltas[base->ref_first].obj_no;
+		struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
 		struct base_data *result = alloc_base_data();
 
 		if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
@@ -957,7 +1010,7 @@ static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 	}
 
 	if (base->ofs_first <= base->ofs_last) {
-		struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
+		struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
 		struct base_data *result = alloc_base_data();
 
 		assert(child->real_type == OBJ_OFS_DELTA);
@@ -993,15 +1046,20 @@ static void find_unresolved_deltas(struct base_data *base)
 	}
 }
 
-static int compare_delta_entry(const void *a, const void *b)
+static int compare_ofs_delta_entry(const void *a, const void *b)
 {
-	const struct delta_entry *delta_a = a;
-	const struct delta_entry *delta_b = b;
+	const struct ofs_delta_entry *delta_a = a;
+	const struct ofs_delta_entry *delta_b = b;
 
-	/* group by type (ref vs ofs) and then by value (sha-1 or offset) */
-	return compare_delta_bases(&delta_a->base, &delta_b->base,
-				   objects[delta_a->obj_no].type,
-				   objects[delta_b->obj_no].type);
+	return delta_a->offset - delta_b->offset;
+}
+
+static int compare_ref_delta_entry(const void *a, const void *b)
+{
+	const struct ref_delta_entry *delta_a = a;
+	const struct ref_delta_entry *delta_b = b;
+
+	return hashcmp(delta_a->sha1, delta_b->sha1);
 }
 
 static void resolve_base(struct object_entry *obj)
@@ -1047,7 +1105,8 @@ static void *threaded_second_pass(void *data)
 static void parse_pack_objects(unsigned char *sha1)
 {
 	int i, nr_delays = 0;
-	struct delta_entry *delta = deltas;
+	struct ofs_delta_entry *ofs_delta = ofs_deltas;
+	unsigned char ref_delta_sha1[20];
 	struct stat st;
 
 	if (verbose)
@@ -1056,12 +1115,18 @@ static void parse_pack_objects(unsigned char *sha1)
 				nr_objects);
 	for (i = 0; i < nr_objects; i++) {
 		struct object_entry *obj = &objects[i];
-		void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
+		void *data = unpack_raw_entry(obj, &ofs_delta->offset,
+					      ref_delta_sha1, obj->idx.sha1);
 		obj->real_type = obj->type;
-		if (is_delta_type(obj->type)) {
-			nr_deltas++;
-			delta->obj_no = i;
-			delta++;
+		if (obj->type == OBJ_OFS_DELTA) {
+			nr_ofs_deltas++;
+			ofs_delta->obj_no = i;
+			ofs_delta++;
+		} else if (obj->type == OBJ_REF_DELTA) {
+			ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
+			hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
+			ref_deltas[nr_ref_deltas].obj_no = i;
+			nr_ref_deltas++;
 		} else if (!data) {
 			/* large blobs, check later */
 			obj->real_type = OBJ_BAD;
@@ -1112,15 +1177,18 @@ static void resolve_deltas(void)
 {
 	int i;
 
-	if (!nr_deltas)
+	if (!nr_ofs_deltas && !nr_ref_deltas)
 		return;
 
 	/* Sort deltas by base SHA1/offset for fast searching */
-	qsort(deltas, nr_deltas, sizeof(struct delta_entry),
-	      compare_delta_entry);
+	qsort(ofs_deltas, nr_ofs_deltas, sizeof(struct ofs_delta_entry),
+	      compare_ofs_delta_entry);
+	qsort(ref_deltas, nr_ref_deltas, sizeof(struct ref_delta_entry),
+	      compare_ref_delta_entry);
 
 	if (verbose)
-		progress = start_progress(_("Resolving deltas"), nr_deltas);
+		progress = start_progress(_("Resolving deltas"),
+					  nr_ref_deltas + nr_ofs_deltas);
 
 #ifndef NO_PTHREADS
 	nr_dispatched = 0;
@@ -1158,7 +1226,7 @@ static void resolve_deltas(void)
 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
 {
-	if (nr_deltas == nr_resolved_deltas) {
+	if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
 		stop_progress(&progress);
 		/* Flush remaining pack final 20-byte SHA1. */
 		flush();
@@ -1169,7 +1237,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 		struct sha1file *f;
 		unsigned char read_sha1[20], tail_sha1[20];
 		struct strbuf msg = STRBUF_INIT;
-		int nr_unresolved = nr_deltas - nr_resolved_deltas;
+		int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
 		int nr_objects_initial = nr_objects;
 		if (nr_unresolved <= 0)
 			die(_("confusion beyond insanity"));
@@ -1191,11 +1259,11 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 			die(_("Unexpected tail checksum for %s "
 			      "(disk corruption?)"), curr_pack);
 	}
-	if (nr_deltas != nr_resolved_deltas)
+	if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
 		die(Q_("pack has %d unresolved delta",
 		       "pack has %d unresolved deltas",
-		       nr_deltas - nr_resolved_deltas),
-		    nr_deltas - nr_resolved_deltas);
+		       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
+		    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
 }
 
 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
@@ -1254,14 +1322,14 @@ static struct object_entry *append_obj_to_pack(struct sha1file *f,
 
 static int delta_pos_compare(const void *_a, const void *_b)
 {
-	struct delta_entry *a = *(struct delta_entry **)_a;
-	struct delta_entry *b = *(struct delta_entry **)_b;
+	struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
+	struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
 	return a->obj_no - b->obj_no;
 }
 
 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
 {
-	struct delta_entry **sorted_by_pos;
+	struct ref_delta_entry **sorted_by_pos;
 	int i, n = 0;
 
 	/*
@@ -1275,28 +1343,25 @@ static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
 	 * resolving deltas in the same order as their position in the pack.
 	 */
 	sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
-	for (i = 0; i < nr_deltas; i++) {
-		if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
-			continue;
-		sorted_by_pos[n++] = &deltas[i];
-	}
+	for (i = 0; i < nr_ref_deltas; i++)
+		sorted_by_pos[n++] = &ref_deltas[i];
 	qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 
 	for (i = 0; i < n; i++) {
-		struct delta_entry *d = sorted_by_pos[i];
+		struct ref_delta_entry *d = sorted_by_pos[i];
 		enum object_type type;
 		struct base_data *base_obj = alloc_base_data();
 
 		if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 			continue;
-		base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
+		base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
 		if (!base_obj->data)
 			continue;
 
-		if (check_sha1_signature(d->base.sha1, base_obj->data,
+		if (check_sha1_signature(d->sha1, base_obj->data,
 				base_obj->size, typename(type)))
-			die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
-		base_obj->obj = append_obj_to_pack(f, d->base.sha1,
+			die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
+		base_obj->obj = append_obj_to_pack(f, d->sha1,
 					base_obj->data, base_obj->size, type);
 		find_unresolved_deltas(base_obj);
 		display_progress(progress, nr_resolved_deltas);
@@ -1488,7 +1553,7 @@ static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
 
 static void show_pack_info(int stat_only)
 {
-	int i, baseobjects = nr_objects - nr_deltas;
+	int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
 	unsigned long *chain_histogram = NULL;
 
 	if (deepest_delta)
@@ -1498,7 +1563,7 @@ static void show_pack_info(int stat_only)
 		struct object_entry *obj = &objects[i];
 
 		if (is_delta_type(obj->type))
-			chain_histogram[obj->delta_depth - 1]++;
+			chain_histogram[obj_stat[i].delta_depth - 1]++;
 		if (stat_only)
 			continue;
 		printf("%s %-6s %lu %lu %"PRIuMAX,
@@ -1507,8 +1572,8 @@ static void show_pack_info(int stat_only)
 		       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
 		       (uintmax_t)obj->idx.offset);
 		if (is_delta_type(obj->type)) {
-			struct object_entry *bobj = &objects[obj->base_object_no];
-			printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
+			struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
+			printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
 		}
 		putchar('\n');
 	}
@@ -1671,11 +1736,14 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	curr_pack = open_pack_file(pack_name);
 	parse_pack_header();
 	objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
-	deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
+	if (show_stat)
+		obj_stat = xcalloc(nr_objects + 1, sizeof(struct object_stat));
+	ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
 	parse_pack_objects(pack_sha1);
 	resolve_deltas();
 	conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
-	free(deltas);
+	free(ofs_deltas);
+	free(ref_deltas);
 	if (strict)
 		foreign_nr = check_objects();
 
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 6723d39c3b..4335738135 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -182,6 +182,20 @@ static int git_init_db_config(const char *k, const char *v, void *cb)
 	return 0;
 }
 
+/*
+ * If the git_dir is not directly inside the working tree, then git will not
+ * find it by default, and we need to set the worktree explicitly.
+ */
+static int needs_work_tree_config(const char *git_dir, const char *work_tree)
+{
+	if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
+		return 0;
+	if (skip_prefix(git_dir, work_tree, &git_dir) &&
+	    !strcmp(git_dir, "/.git"))
+		return 0;
+	return 1;
+}
+
 static int create_default_files(const char *template_path)
 {
 	const char *git_dir = get_git_dir();
@@ -274,10 +288,8 @@ static int create_default_files(const char *template_path)
 		/* allow template config file to override the default */
 		if (log_all_ref_updates == -1)
 		    git_config_set("core.logallrefupdates", "true");
-		if (!starts_with(git_dir, work_tree) ||
-		    strcmp(git_dir + strlen(work_tree), "/.git")) {
+		if (needs_work_tree_config(git_dir, work_tree))
 			git_config_set("core.worktree", work_tree);
-		}
 	}
 
 	if (!reinit) {
@@ -350,7 +362,6 @@ int set_git_dir_init(const char *git_dir, const char *real_git_dir,
 static void separate_git_dir(const char *git_dir)
 {
 	struct stat st;
-	FILE *fp;
 
 	if (!stat(git_link, &st)) {
 		const char *src;
@@ -366,11 +377,7 @@ static void separate_git_dir(const char *git_dir)
 			die_errno(_("unable to move %s to %s"), src, git_dir);
 	}
 
-	fp = fopen(git_link, "w");
-	if (!fp)
-		die(_("Could not create git link %s"), git_link);
-	fprintf(fp, "gitdir: %s\n", git_dir);
-	fclose(fp);
+	write_file(git_link, 1, "gitdir: %s\n", git_dir);
 }
 
 int init_db(const char *template_dir, unsigned int flags)
diff --git a/builtin/log.c b/builtin/log.c
index dd8f3fcfc4..4c4e6be28c 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -38,7 +38,7 @@ static const char *fmt_patch_subject_prefix = "PATCH";
 static const char *fmt_pretty;
 
 static const char * const builtin_log_usage[] = {
-	N_("git log [<options>] [<revision range>] [[--] <path>...]"),
+	N_("git log [<options>] [<revision-range>] [[--] <path>...]"),
 	N_("git show [<options>] <object>..."),
 	NULL
 };
diff --git a/builtin/merge.c b/builtin/merge.c
index 3b0f8f96d4..f89f60e11a 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -492,8 +492,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 	}
 	if (len) {
 		struct strbuf truname = STRBUF_INIT;
-		strbuf_addstr(&truname, "refs/heads/");
-		strbuf_addstr(&truname, remote);
+		strbuf_addf(&truname, "refs/heads/%s", remote);
 		strbuf_setlen(&truname, truname.len - len);
 		if (ref_exists(truname.buf)) {
 			strbuf_addf(msg,
@@ -504,28 +503,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
 			strbuf_release(&truname);
 			goto cleanup;
 		}
-	}
-
-	if (!strcmp(remote, "FETCH_HEAD") &&
-			!access(git_path("FETCH_HEAD"), R_OK)) {
-		const char *filename;
-		FILE *fp;
-		struct strbuf line = STRBUF_INIT;
-		char *ptr;
-
-		filename = git_path("FETCH_HEAD");
-		fp = fopen(filename, "r");
-		if (!fp)
-			die_errno(_("could not open '%s' for reading"),
-				  filename);
-		strbuf_getline(&line, fp, '\n');
-		fclose(fp);
-		ptr = strstr(line.buf, "\tnot-for-merge\t");
-		if (ptr)
-			strbuf_remove(&line, ptr-line.buf+1, 13);
-		strbuf_addbuf(msg, &line);
-		strbuf_release(&line);
-		goto cleanup;
+		strbuf_release(&truname);
 	}
 
 	if (remote_head->util) {
@@ -1037,28 +1015,24 @@ static int default_edit_option(void)
 		st_stdin.st_mode == st_stdout.st_mode);
 }
 
-static struct commit_list *collect_parents(struct commit *head_commit,
-					   int *head_subsumed,
-					   int argc, const char **argv)
+static struct commit_list *reduce_parents(struct commit *head_commit,
+					  int *head_subsumed,
+					  struct commit_list *remoteheads)
 {
-	int i;
-	struct commit_list *remoteheads = NULL, *parents, *next;
-	struct commit_list **remotes = &remoteheads;
+	struct commit_list *parents, *next, **remotes = &remoteheads;
 
-	if (head_commit)
-		remotes = &commit_list_insert(head_commit, remotes)->next;
-	for (i = 0; i < argc; i++) {
-		struct commit *commit = get_merge_parent(argv[i]);
-		if (!commit)
-			help_unknown_ref(argv[i], "merge",
-					 "not something we can merge");
-		remotes = &commit_list_insert(commit, remotes)->next;
-	}
-	*remotes = NULL;
+	/*
+	 * Is the current HEAD reachable from another commit being
+	 * merged?  If so we do not want to record it as a parent of
+	 * the resulting merge, unless --no-ff is given.  We will flip
+	 * this variable to 0 when we find HEAD among the independent
+	 * tips being merged.
+	 */
+	*head_subsumed = 1;
 
+	/* Find what parents to record by checking independent ones. */
 	parents = reduce_heads(remoteheads);
 
-	*head_subsumed = 1; /* we will flip this to 0 when we find it */
 	for (remoteheads = NULL, remotes = &remoteheads;
 	     parents;
 	     parents = next) {
@@ -1068,7 +1042,119 @@ static struct commit_list *collect_parents(struct commit *head_commit,
 			*head_subsumed = 0;
 		else
 			remotes = &commit_list_insert(commit, remotes)->next;
+		free(parents);
+	}
+	return remoteheads;
+}
+
+static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
+{
+	struct fmt_merge_msg_opts opts;
+
+	memset(&opts, 0, sizeof(opts));
+	opts.add_title = !have_message;
+	opts.shortlog_len = shortlog_len;
+	opts.credit_people = (0 < option_edit);
+
+	fmt_merge_msg(merge_names, merge_msg, &opts);
+	if (merge_msg->len)
+		strbuf_setlen(merge_msg, merge_msg->len - 1);
+}
+
+static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
+{
+	const char *filename;
+	int fd, pos, npos;
+	struct strbuf fetch_head_file = STRBUF_INIT;
+
+	if (!merge_names)
+		merge_names = &fetch_head_file;
+
+	filename = git_path("FETCH_HEAD");
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		die_errno(_("could not open '%s' for reading"), filename);
+
+	if (strbuf_read(merge_names, fd, 0) < 0)
+		die_errno(_("could not read '%s'"), filename);
+	if (close(fd) < 0)
+		die_errno(_("could not close '%s'"), filename);
+
+	for (pos = 0; pos < merge_names->len; pos = npos) {
+		unsigned char sha1[20];
+		char *ptr;
+		struct commit *commit;
+
+		ptr = strchr(merge_names->buf + pos, '\n');
+		if (ptr)
+			npos = ptr - merge_names->buf + 1;
+		else
+			npos = merge_names->len;
+
+		if (npos - pos < 40 + 2 ||
+		    get_sha1_hex(merge_names->buf + pos, sha1))
+			commit = NULL; /* bad */
+		else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
+			continue; /* not-for-merge */
+		else {
+			char saved = merge_names->buf[pos + 40];
+			merge_names->buf[pos + 40] = '\0';
+			commit = get_merge_parent(merge_names->buf + pos);
+			merge_names->buf[pos + 40] = saved;
+		}
+		if (!commit) {
+			if (ptr)
+				*ptr = '\0';
+			die("not something we can merge in %s: %s",
+			    filename, merge_names->buf + pos);
+		}
+		remotes = &commit_list_insert(commit, remotes)->next;
+	}
+
+	if (merge_names == &fetch_head_file)
+		strbuf_release(&fetch_head_file);
+}
+
+static struct commit_list *collect_parents(struct commit *head_commit,
+					   int *head_subsumed,
+					   int argc, const char **argv,
+					   struct strbuf *merge_msg)
+{
+	int i;
+	struct commit_list *remoteheads = NULL;
+	struct commit_list **remotes = &remoteheads;
+	struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
+
+	if (merge_msg && (!have_message || shortlog_len))
+		autogen = &merge_names;
+
+	if (head_commit)
+		remotes = &commit_list_insert(head_commit, remotes)->next;
+
+	if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
+		handle_fetch_head(remotes, autogen);
+		remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
+	} else {
+		for (i = 0; i < argc; i++) {
+			struct commit *commit = get_merge_parent(argv[i]);
+			if (!commit)
+				help_unknown_ref(argv[i], "merge",
+						 "not something we can merge");
+			remotes = &commit_list_insert(commit, remotes)->next;
+		}
+		remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
+		if (autogen) {
+			struct commit_list *p;
+			for (p = remoteheads; p; p = p->next)
+				merge_name(merge_remote_util(p->item)->name, autogen);
+		}
 	}
+
+	if (autogen) {
+		prepare_merge_message(autogen, merge_msg);
+		strbuf_release(autogen);
+	}
+
 	return remoteheads;
 }
 
@@ -1158,61 +1244,62 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		option_commit = 0;
 	}
 
-	if (!abort_current_merge) {
-		if (!argc) {
-			if (default_to_upstream)
-				argc = setup_with_upstream(&argv);
-			else
-				die(_("No commit specified and merge.defaultToUpstream not set."));
-		} else if (argc == 1 && !strcmp(argv[0], "-"))
-			argv[0] = "@{-1}";
+	if (!argc) {
+		if (default_to_upstream)
+			argc = setup_with_upstream(&argv);
+		else
+			die(_("No commit specified and merge.defaultToUpstream not set."));
+	} else if (argc == 1 && !strcmp(argv[0], "-")) {
+		argv[0] = "@{-1}";
 	}
+
 	if (!argc)
 		usage_with_options(builtin_merge_usage,
 			builtin_merge_options);
 
-	/*
-	 * This could be traditional "merge <msg> HEAD <commit>..."  and
-	 * the way we can tell it is to see if the second token is HEAD,
-	 * but some people might have misused the interface and used a
-	 * commit-ish that is the same as HEAD there instead.
-	 * Traditional format never would have "-m" so it is an
-	 * additional safety measure to check for it.
-	 */
-
-	if (!have_message && head_commit &&
-	    is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
-		strbuf_addstr(&merge_msg, argv[0]);
-		head_arg = argv[1];
-		argv += 2;
-		argc -= 2;
-		remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
-	} else if (!head_commit) {
+	if (!head_commit) {
 		struct commit *remote_head;
 		/*
 		 * If the merged head is a valid one there is no reason
 		 * to forbid "git merge" into a branch yet to be born.
 		 * We do the same for "git pull".
 		 */
-		if (argc != 1)
-			die(_("Can merge only exactly one commit into "
-				"empty head"));
 		if (squash)
 			die(_("Squash commit into empty head not supported yet"));
 		if (fast_forward == FF_NO)
 			die(_("Non-fast-forward commit does not make sense into "
 			    "an empty head"));
-		remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
+		remoteheads = collect_parents(head_commit, &head_subsumed,
+					      argc, argv, NULL);
 		remote_head = remoteheads->item;
 		if (!remote_head)
 			die(_("%s - not something we can merge"), argv[0]);
+		if (remoteheads->next)
+			die(_("Can merge only exactly one commit into empty head"));
 		read_empty(remote_head->object.sha1, 0);
 		update_ref("initial pull", "HEAD", remote_head->object.sha1,
 			   NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 		goto done;
-	} else {
-		struct strbuf merge_names = STRBUF_INIT;
+	}
 
+	/*
+	 * This could be traditional "merge <msg> HEAD <commit>..."  and
+	 * the way we can tell it is to see if the second token is HEAD,
+	 * but some people might have misused the interface and used a
+	 * commit-ish that is the same as HEAD there instead.
+	 * Traditional format never would have "-m" so it is an
+	 * additional safety measure to check for it.
+	 */
+	if (!have_message &&
+	    is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
+		warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
+		strbuf_addstr(&merge_msg, argv[0]);
+		head_arg = argv[1];
+		argv += 2;
+		argc -= 2;
+		remoteheads = collect_parents(head_commit, &head_subsumed,
+					      argc, argv, NULL);
+	} else {
 		/* We are invoked directly as the first-class UI. */
 		head_arg = "HEAD";
 
@@ -1221,21 +1308,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		 * the standard merge summary message to be appended
 		 * to the given message.
 		 */
-		remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
-		for (p = remoteheads; p; p = p->next)
-			merge_name(merge_remote_util(p->item)->name, &merge_names);
-
-		if (!have_message || shortlog_len) {
-			struct fmt_merge_msg_opts opts;
-			memset(&opts, 0, sizeof(opts));
-			opts.add_title = !have_message;
-			opts.shortlog_len = shortlog_len;
-			opts.credit_people = (0 < option_edit);
-
-			fmt_merge_msg(&merge_names, &merge_msg, &opts);
-			if (merge_msg.len)
-				strbuf_setlen(&merge_msg, merge_msg.len - 1);
-		}
+		remoteheads = collect_parents(head_commit, &head_subsumed,
+					      argc, argv, &merge_msg);
 	}
 
 	if (!head_commit || !argc)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c3a75166bd..c067107a6a 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -961,10 +961,8 @@ static int want_object_in_pack(const unsigned char *sha1,
 		off_t offset = find_pack_entry_one(sha1, p);
 		if (offset) {
 			if (!*found_pack) {
-				if (!is_pack_valid(p)) {
-					warning("packfile %s cannot be accessed", p->pack_name);
+				if (!is_pack_valid(p))
 					continue;
-				}
 				*found_offset = offset;
 				*found_pack = p;
 			}
diff --git a/builtin/patch-id.c b/builtin/patch-id.c
index 77db8739b5..ba34dac4d2 100644
--- a/builtin/patch-id.c
+++ b/builtin/patch-id.c
@@ -1,14 +1,14 @@
 #include "builtin.h"
 
-static void flush_current_id(int patchlen, unsigned char *id, unsigned char *result)
+static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result)
 {
 	char name[50];
 
 	if (!patchlen)
 		return;
 
-	memcpy(name, sha1_to_hex(id), 41);
-	printf("%s %s\n", sha1_to_hex(result), name);
+	memcpy(name, oid_to_hex(id), GIT_SHA1_HEXSZ + 1);
+	printf("%s %s\n", oid_to_hex(result), name);
 }
 
 static int remove_space(char *line)
@@ -53,23 +53,23 @@ static int scan_hunk_header(const char *p, int *p_before, int *p_after)
 	return 1;
 }
 
-static void flush_one_hunk(unsigned char *result, git_SHA_CTX *ctx)
+static void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
 {
-	unsigned char hash[20];
+	unsigned char hash[GIT_SHA1_RAWSZ];
 	unsigned short carry = 0;
 	int i;
 
 	git_SHA1_Final(hash, ctx);
 	git_SHA1_Init(ctx);
 	/* 20-byte sum, with carry */
-	for (i = 0; i < 20; ++i) {
-		carry += result[i] + hash[i];
-		result[i] = carry;
+	for (i = 0; i < GIT_SHA1_RAWSZ; ++i) {
+		carry += result->hash[i] + hash[i];
+		result->hash[i] = carry;
 		carry >>= 8;
 	}
 }
 
-static int get_one_patchid(unsigned char *next_sha1, unsigned char *result,
+static int get_one_patchid(struct object_id *next_oid, struct object_id *result,
 			   struct strbuf *line_buf, int stable)
 {
 	int patchlen = 0, found_next = 0;
@@ -77,7 +77,7 @@ static int get_one_patchid(unsigned char *next_sha1, unsigned char *result,
 	git_SHA_CTX ctx;
 
 	git_SHA1_Init(&ctx);
-	hashclr(result);
+	oidclr(result);
 
 	while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
 		char *line = line_buf->buf;
@@ -93,7 +93,7 @@ static int get_one_patchid(unsigned char *next_sha1, unsigned char *result,
 		else if (!memcmp(line, "\\ ", 2) && 12 < strlen(line))
 			continue;
 
-		if (!get_sha1_hex(p, next_sha1)) {
+		if (!get_oid_hex(p, next_oid)) {
 			found_next = 1;
 			break;
 		}
@@ -143,7 +143,7 @@ static int get_one_patchid(unsigned char *next_sha1, unsigned char *result,
 	}
 
 	if (!found_next)
-		hashclr(next_sha1);
+		oidclr(next_oid);
 
 	flush_one_hunk(result, &ctx);
 
@@ -152,15 +152,15 @@ static int get_one_patchid(unsigned char *next_sha1, unsigned char *result,
 
 static void generate_id_list(int stable)
 {
-	unsigned char sha1[20], n[20], result[20];
+	struct object_id oid, n, result;
 	int patchlen;
 	struct strbuf line_buf = STRBUF_INIT;
 
-	hashclr(sha1);
+	oidclr(&oid);
 	while (!feof(stdin)) {
-		patchlen = get_one_patchid(n, result, &line_buf, stable);
-		flush_current_id(patchlen, sha1, result);
-		hashcpy(sha1, n);
+		patchlen = get_one_patchid(&n, &result, &line_buf, stable);
+		flush_current_id(patchlen, &oid, &result);
+		oidcpy(&oid, &n);
 	}
 	strbuf_release(&line_buf);
 }
diff --git a/builtin/prune.c b/builtin/prune.c
index 17094ad954..0c73246c72 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -76,6 +76,95 @@ static int prune_subdir(int nr, const char *path, void *data)
 	return 0;
 }
 
+static int prune_worktree(const char *id, struct strbuf *reason)
+{
+	struct stat st;
+	char *path;
+	int fd, len;
+
+	if (!is_directory(git_path("worktrees/%s", id))) {
+		strbuf_addf(reason, _("Removing worktrees/%s: not a valid directory"), id);
+		return 1;
+	}
+	if (file_exists(git_path("worktrees/%s/locked", id)))
+		return 0;
+	if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
+		strbuf_addf(reason, _("Removing worktrees/%s: gitdir file does not exist"), id);
+		return 1;
+	}
+	fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
+	if (fd < 0) {
+		strbuf_addf(reason, _("Removing worktrees/%s: unable to read gitdir file (%s)"),
+			    id, strerror(errno));
+		return 1;
+	}
+	len = st.st_size;
+	path = xmalloc(len + 1);
+	read_in_full(fd, path, len);
+	close(fd);
+	while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
+		len--;
+	if (!len) {
+		strbuf_addf(reason, _("Removing worktrees/%s: invalid gitdir file"), id);
+		free(path);
+		return 1;
+	}
+	path[len] = '\0';
+	if (!file_exists(path)) {
+		struct stat st_link;
+		free(path);
+		/*
+		 * the repo is moved manually and has not been
+		 * accessed since?
+		 */
+		if (!stat(git_path("worktrees/%s/link", id), &st_link) &&
+		    st_link.st_nlink > 1)
+			return 0;
+		if (st.st_mtime <= expire) {
+			strbuf_addf(reason, _("Removing worktrees/%s: gitdir file points to non-existent location"), id);
+			return 1;
+		} else {
+			return 0;
+		}
+	}
+	free(path);
+	return 0;
+}
+
+static void prune_worktrees(void)
+{
+	struct strbuf reason = STRBUF_INIT;
+	struct strbuf path = STRBUF_INIT;
+	DIR *dir = opendir(git_path("worktrees"));
+	struct dirent *d;
+	int ret;
+	if (!dir)
+		return;
+	while ((d = readdir(dir)) != NULL) {
+		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+			continue;
+		strbuf_reset(&reason);
+		if (!prune_worktree(d->d_name, &reason))
+			continue;
+		if (show_only || verbose)
+			printf("%s\n", reason.buf);
+		if (show_only)
+			continue;
+		strbuf_reset(&path);
+		strbuf_addstr(&path, git_path("worktrees/%s", d->d_name));
+		ret = remove_dir_recursively(&path, 0);
+		if (ret < 0 && errno == ENOTDIR)
+			ret = unlink(path.buf);
+		if (ret)
+			error(_("failed to remove: %s"), strerror(errno));
+	}
+	closedir(dir);
+	if (!show_only)
+		rmdir(git_path("worktrees"));
+	strbuf_release(&reason);
+	strbuf_release(&path);
+}
+
 /*
  * Write errors (particularly out of space) can result in
  * failed temporary packs (and more rarely indexes and other
@@ -102,10 +191,12 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
 	struct progress *progress = NULL;
+	int do_prune_worktrees = 0;
 	const struct option options[] = {
 		OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
 		OPT__VERBOSE(&verbose, N_("report pruned objects")),
 		OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
+		OPT_BOOL(0, "worktrees", &do_prune_worktrees, N_("prune .git/worktrees")),
 		OPT_EXPIRY_DATE(0, "expire", &expire,
 				N_("expire objects older than <time>")),
 		OPT_END()
@@ -119,6 +210,14 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 	init_revisions(&revs, prefix);
 
 	argc = parse_options(argc, argv, prefix, options, prune_usage, 0);
+
+	if (do_prune_worktrees) {
+		if (argc)
+			die(_("--worktrees does not take extra arguments"));
+		prune_worktrees();
+		return 0;
+	}
+
 	while (argc--) {
 		unsigned char sha1[20];
 		const char *name = *argv++;
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 5292bb5a50..d2ec52bca9 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1008,7 +1008,7 @@ static void run_update_post_hook(struct command *commands)
 	int argc;
 	const char **argv;
 	struct child_process proc = CHILD_PROCESS_INIT;
-	char *hook;
+	const char *hook;
 
 	hook = find_hook("post-update");
 	for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
diff --git a/builtin/remote.c b/builtin/remote.c
index 5d3ab906bc..ad57fc984e 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -584,7 +584,7 @@ static int migrate_file(struct remote *remote)
 {
 	struct strbuf buf = STRBUF_INIT;
 	int i;
-	char *path = NULL;
+	const char *path = NULL;
 
 	strbuf_addf(&buf, "remote.%s.url", remote->name);
 	for (i = 0; i < remote->url_nr; i++)
diff --git a/builtin/repack.c b/builtin/repack.c
index f2edeb0f4c..af7340c7ba 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -285,7 +285,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	failed = 0;
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
-			char *fname, *fname_old;
+			const char *fname_old;
+			char *fname;
 			fname = mkpathdup("%s/pack-%s%s", packdir,
 						item->string, exts[ext].name);
 			if (!file_exists(fname)) {
@@ -313,7 +314,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (failed) {
 		struct string_list rollback_failure = STRING_LIST_INIT_DUP;
 		for_each_string_list_item(item, &rollback) {
-			char *fname, *fname_old;
+			const char *fname_old;
+			char *fname;
 			fname = mkpathdup("%s/%s", packdir, item->string);
 			fname_old = mkpath("%s/old-%s", packdir, item->string);
 			if (rename(fname_old, fname))
@@ -366,7 +368,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	/* Remove the "old-" files */
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
-			char *fname;
+			const char *fname;
 			fname = mkpath("%s/old-%s%s",
 					packdir,
 					item->string,
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 3626c61da6..4d10dd9545 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -533,6 +533,13 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 
+		if (!strcmp(arg, "--git-path")) {
+			if (!argv[i + 1])
+				die("--git-path requires an argument");
+			puts(git_path("%s", argv[i + 1]));
+			i++;
+			continue;
+		}
 		if (as_is) {
 			if (show_file(arg, output_prefix) && as_is < 2)
 				verify_filename(prefix, arg, 0);
@@ -755,6 +762,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				free(cwd);
 				continue;
 			}
+			if (!strcmp(arg, "--git-common-dir")) {
+				puts(get_git_common_dir());
+				continue;
+			}
 			if (!strcmp(arg, "--resolve-git-dir")) {
 				const char *gitdir = argv[++i];
 				if (!gitdir)
diff --git a/builtin/rm.c b/builtin/rm.c
index 3304bff42a..80b972f92f 100644
--- a/builtin/rm.c
+++ b/builtin/rm.c
@@ -84,7 +84,6 @@ static int check_submodules_use_gitfiles(void)
 		const char *name = list.entry[i].name;
 		int pos;
 		const struct cache_entry *ce;
-		struct stat st;
 
 		pos = cache_name_pos(name, strlen(name));
 		if (pos < 0) {
@@ -95,7 +94,7 @@ static int check_submodules_use_gitfiles(void)
 		ce = active_cache[pos];
 
 		if (!S_ISGITLINK(ce->ce_mode) ||
-		    (lstat(ce->name, &st) < 0) ||
+		    !file_exists(ce->name) ||
 		    is_empty_dir(name))
 			continue;
 
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index f3fb5fb2bf..e69fb7c489 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -718,7 +718,7 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 	}
 
 	/* If nothing is specified, show all branches by default */
-	if (ac + all_heads + all_remotes == 0)
+	if (ac <= topics && all_heads + all_remotes == 0)
 		all_heads = 1;
 
 	if (reflog) {
@@ -785,13 +785,13 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 		}
 		free(ref);
 	}
-	else if (all_heads + all_remotes)
-		snarf_refs(all_heads, all_remotes);
 	else {
 		while (0 < ac) {
 			append_one_rev(*av);
 			ac--; av++;
 		}
+		if (all_heads + all_remotes)
+			snarf_refs(all_heads, all_remotes);
 	}
 
 	head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 6271b54adc..7431938fa6 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -33,6 +33,7 @@ static int mark_valid_only;
 static int mark_skip_worktree_only;
 #define MARK_FLAG 1
 #define UNMARK_FLAG 2
+static struct strbuf mtime_dir = STRBUF_INIT;
 
 __attribute__((format (printf, 1, 2)))
 static void report(const char *fmt, ...)
@@ -48,6 +49,166 @@ static void report(const char *fmt, ...)
 	va_end(vp);
 }
 
+static void remove_test_directory(void)
+{
+	if (mtime_dir.len)
+		remove_dir_recursively(&mtime_dir, 0);
+}
+
+static const char *get_mtime_path(const char *path)
+{
+	static struct strbuf sb = STRBUF_INIT;
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s/%s", mtime_dir.buf, path);
+	return sb.buf;
+}
+
+static void xmkdir(const char *path)
+{
+	path = get_mtime_path(path);
+	if (mkdir(path, 0700))
+		die_errno(_("failed to create directory %s"), path);
+}
+
+static int xstat_mtime_dir(struct stat *st)
+{
+	if (stat(mtime_dir.buf, st))
+		die_errno(_("failed to stat %s"), mtime_dir.buf);
+	return 0;
+}
+
+static int create_file(const char *path)
+{
+	int fd;
+	path = get_mtime_path(path);
+	fd = open(path, O_CREAT | O_RDWR, 0644);
+	if (fd < 0)
+		die_errno(_("failed to create file %s"), path);
+	return fd;
+}
+
+static void xunlink(const char *path)
+{
+	path = get_mtime_path(path);
+	if (unlink(path))
+		die_errno(_("failed to delete file %s"), path);
+}
+
+static void xrmdir(const char *path)
+{
+	path = get_mtime_path(path);
+	if (rmdir(path))
+		die_errno(_("failed to delete directory %s"), path);
+}
+
+static void avoid_racy(void)
+{
+	/*
+	 * not use if we could usleep(10) if USE_NSEC is defined. The
+	 * field nsec could be there, but the OS could choose to
+	 * ignore it?
+	 */
+	sleep(1);
+}
+
+static int test_if_untracked_cache_is_supported(void)
+{
+	struct stat st;
+	struct stat_data base;
+	int fd, ret = 0;
+
+	strbuf_addstr(&mtime_dir, "mtime-test-XXXXXX");
+	if (!mkdtemp(mtime_dir.buf))
+		die_errno("Could not make temporary directory");
+
+	fprintf(stderr, _("Testing "));
+	atexit(remove_test_directory);
+	xstat_mtime_dir(&st);
+	fill_stat_data(&base, &st);
+	fputc('.', stderr);
+
+	avoid_racy();
+	fd = create_file("newfile");
+	xstat_mtime_dir(&st);
+	if (!match_stat_data(&base, &st)) {
+		close(fd);
+		fputc('\n', stderr);
+		fprintf_ln(stderr,_("directory stat info does not "
+				    "change after adding a new file"));
+		goto done;
+	}
+	fill_stat_data(&base, &st);
+	fputc('.', stderr);
+
+	avoid_racy();
+	xmkdir("new-dir");
+	xstat_mtime_dir(&st);
+	if (!match_stat_data(&base, &st)) {
+		close(fd);
+		fputc('\n', stderr);
+		fprintf_ln(stderr, _("directory stat info does not change "
+				     "after adding a new directory"));
+		goto done;
+	}
+	fill_stat_data(&base, &st);
+	fputc('.', stderr);
+
+	avoid_racy();
+	write_or_die(fd, "data", 4);
+	close(fd);
+	xstat_mtime_dir(&st);
+	if (match_stat_data(&base, &st)) {
+		fputc('\n', stderr);
+		fprintf_ln(stderr, _("directory stat info changes "
+				     "after updating a file"));
+		goto done;
+	}
+	fputc('.', stderr);
+
+	avoid_racy();
+	close(create_file("new-dir/new"));
+	xstat_mtime_dir(&st);
+	if (match_stat_data(&base, &st)) {
+		fputc('\n', stderr);
+		fprintf_ln(stderr, _("directory stat info changes after "
+				     "adding a file inside subdirectory"));
+		goto done;
+	}
+	fputc('.', stderr);
+
+	avoid_racy();
+	xunlink("newfile");
+	xstat_mtime_dir(&st);
+	if (!match_stat_data(&base, &st)) {
+		fputc('\n', stderr);
+		fprintf_ln(stderr, _("directory stat info does not "
+				     "change after deleting a file"));
+		goto done;
+	}
+	fill_stat_data(&base, &st);
+	fputc('.', stderr);
+
+	avoid_racy();
+	xunlink("new-dir/new");
+	xrmdir("new-dir");
+	xstat_mtime_dir(&st);
+	if (!match_stat_data(&base, &st)) {
+		fputc('\n', stderr);
+		fprintf_ln(stderr, _("directory stat info does not "
+				     "change after deleting a directory"));
+		goto done;
+	}
+
+	if (rmdir(mtime_dir.buf))
+		die_errno(_("failed to delete directory %s"), mtime_dir.buf);
+	fprintf_ln(stderr, _(" OK"));
+	ret = 1;
+
+done:
+	strbuf_release(&mtime_dir);
+	return ret;
+}
+
 static int mark_ce_flags(const char *path, int flag, int mark)
 {
 	int namelen = strlen(path);
@@ -532,10 +693,9 @@ static int do_unresolve(int ac, const char **av,
 
 	for (i = 1; i < ac; i++) {
 		const char *arg = av[i];
-		const char *p = prefix_path(prefix, prefix_length, arg);
+		char *p = prefix_path(prefix, prefix_length, arg);
 		err |= unresolve_one(p);
-		if (p < arg || p > arg + strlen(arg))
-			free((char *)p);
+		free(p);
 	}
 	return err;
 }
@@ -742,6 +902,7 @@ static int reupdate_callback(struct parse_opt_ctx_t *ctx,
 int cmd_update_index(int argc, const char **argv, const char *prefix)
 {
 	int newfd, entries, has_errors = 0, line_termination = '\n';
+	int untracked_cache = -1;
 	int read_from_stdin = 0;
 	int prefix_length = prefix ? strlen(prefix) : 0;
 	int preferred_index_format = 0;
@@ -833,6 +994,10 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			N_("write index in this format")),
 		OPT_BOOL(0, "split-index", &split_index,
 			N_("enable or disable split index")),
+		OPT_BOOL(0, "untracked-cache", &untracked_cache,
+			N_("enable/disable untracked cache")),
+		OPT_SET_INT(0, "force-untracked-cache", &untracked_cache,
+			    N_("enable untracked cache without testing the filesystem"), 2),
 		OPT_END()
 	};
 
@@ -871,14 +1036,14 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		case PARSE_OPT_DONE:
 		{
 			const char *path = ctx.argv[0];
-			const char *p;
+			char *p;
 
 			setup_work_tree();
 			p = prefix_path(prefix, prefix_length, path);
 			update_one(p);
 			if (set_executable_bit)
 				chmod_path(set_executable_bit, p);
-			free((char *)p);
+			free(p);
 			ctx.argc--;
 			ctx.argv++;
 			break;
@@ -909,7 +1074,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 
 		setup_work_tree();
 		while (strbuf_getline(&buf, stdin, line_termination) != EOF) {
-			const char *p;
+			char *p;
 			if (line_termination && buf.buf[0] == '"') {
 				strbuf_reset(&nbuf);
 				if (unquote_c_style(&nbuf, buf.buf, NULL))
@@ -920,7 +1085,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			update_one(p);
 			if (set_executable_bit)
 				chmod_path(set_executable_bit, p);
-			free((char *)p);
+			free(p);
 		}
 		strbuf_release(&nbuf);
 		strbuf_release(&buf);
@@ -939,6 +1104,28 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		the_index.split_index = NULL;
 		the_index.cache_changed |= SOMETHING_CHANGED;
 	}
+	if (untracked_cache > 0) {
+		struct untracked_cache *uc;
+
+		if (untracked_cache < 2) {
+			setup_work_tree();
+			if (!test_if_untracked_cache_is_supported())
+				return 1;
+		}
+		if (!the_index.untracked) {
+			uc = xcalloc(1, sizeof(*uc));
+			strbuf_init(&uc->ident, 100);
+			uc->exclude_per_dir = ".gitignore";
+			/* should be the same flags used by git-status */
+			uc->dir_flags = DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;
+			the_index.untracked = uc;
+		}
+		add_untracked_ident(the_index.untracked);
+		the_index.cache_changed |= UNTRACKED_CHANGED;
+	} else if (!untracked_cache && the_index.untracked) {
+		the_index.untracked = NULL;
+		the_index.cache_changed |= UNTRACKED_CHANGED;
+	}
 
 	if (active_cache_changed) {
 		if (newfd < 0) {
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 8d157eba45..7cffc3a579 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -24,7 +24,7 @@ static struct bulk_checkin_state {
 
 static void finish_bulk_checkin(struct bulk_checkin_state *state)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct strbuf packname = STRBUF_INIT;
 	int i;
 
@@ -36,11 +36,11 @@ static void finish_bulk_checkin(struct bulk_checkin_state *state)
 		unlink(state->pack_tmp_name);
 		goto clear_exit;
 	} else if (state->nr_written == 1) {
-		sha1close(state->f, sha1, CSUM_FSYNC);
+		sha1close(state->f, oid.hash, CSUM_FSYNC);
 	} else {
-		int fd = sha1close(state->f, sha1, 0);
-		fixup_pack_header_footer(fd, sha1, state->pack_tmp_name,
-					 state->nr_written, sha1,
+		int fd = sha1close(state->f, oid.hash, 0);
+		fixup_pack_header_footer(fd, oid.hash, state->pack_tmp_name,
+					 state->nr_written, oid.hash,
 					 state->offset);
 		close(fd);
 	}
@@ -48,7 +48,7 @@ static void finish_bulk_checkin(struct bulk_checkin_state *state)
 	strbuf_addf(&packname, "%s/pack/pack-", get_object_directory());
 	finish_tmp_packfile(&packname, state->pack_tmp_name,
 			    state->written, state->nr_written,
-			    &state->pack_idx_opts, sha1);
+			    &state->pack_idx_opts, oid.hash);
 	for (i = 0; i < state->nr_written; i++)
 		free(state->written[i]);
 
diff --git a/cache.h b/cache.h
index 3d3244ba64..571c98f5e2 100644
--- a/cache.h
+++ b/cache.h
@@ -43,6 +43,14 @@ int git_deflate_end_gently(git_zstream *);
 int git_deflate(git_zstream *, int flush);
 unsigned long git_deflate_bound(git_zstream *, unsigned long);
 
+/* The length in bytes and in hex digits of an object name (SHA-1 value). */
+#define GIT_SHA1_RAWSZ 20
+#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
+
+struct object_id {
+	unsigned char hash[GIT_SHA1_RAWSZ];
+};
+
 #if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
 #define DTYPE(de)	((de)->d_type)
 #else
@@ -289,8 +297,11 @@ static inline unsigned int canon_mode(unsigned int mode)
 #define RESOLVE_UNDO_CHANGED	(1 << 4)
 #define CACHE_TREE_CHANGED	(1 << 5)
 #define SPLIT_INDEX_ORDERED	(1 << 6)
+#define UNTRACKED_CHANGED	(1 << 7)
 
 struct split_index;
+struct untracked_cache;
+
 struct index_state {
 	struct cache_entry **cache;
 	unsigned int version;
@@ -304,6 +315,7 @@ struct index_state {
 	struct hashmap name_hash;
 	struct hashmap dir_hash;
 	unsigned char sha1[20];
+	struct untracked_cache *untracked;
 };
 
 extern struct index_state the_index;
@@ -370,6 +382,7 @@ static inline enum object_type object_type(unsigned int mode)
 
 /* Double-check local_repo_env below if you add to this list. */
 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
+#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
 #define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
 #define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
 #define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
@@ -423,11 +436,13 @@ extern int is_inside_git_dir(void);
 extern char *git_work_tree_cfg;
 extern int is_inside_work_tree(void);
 extern const char *get_git_dir(void);
+extern const char *get_git_common_dir(void);
 extern int is_git_directory(const char *path);
 extern char *get_object_directory(void);
 extern char *get_index_file(void);
 extern char *get_graft_file(void);
 extern int set_git_dir(const char *path);
+extern int get_common_dir(struct strbuf *sb, const char *gitdir);
 extern const char *get_git_namespace(void);
 extern const char *strip_namespace(const char *namespaced_ref);
 extern const char *get_git_work_tree(void);
@@ -552,6 +567,8 @@ extern void fill_stat_data(struct stat_data *sd, struct stat *st);
  * INODE_CHANGED, and DATA_CHANGED.
  */
 extern int match_stat_data(const struct stat_data *sd, struct stat *st);
+extern int match_stat_data_racy(const struct index_state *istate,
+				const struct stat_data *sd, struct stat *st);
 
 extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 
@@ -612,6 +629,7 @@ extern int core_apply_sparse_checkout;
 extern int precomposed_unicode;
 extern int protect_hfs;
 extern int protect_ntfs;
+extern int git_db_env, git_index_env, git_graft_env, git_common_dir_env;
 
 /*
  * Include broken refs in all ref iterations, which will
@@ -682,18 +700,19 @@ extern int check_repository_format(void);
 
 extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
-extern char *git_snpath(char *buf, size_t n, const char *fmt, ...)
-	__attribute__((format (printf, 3, 4)));
+extern void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
+	__attribute__((format (printf, 2, 3)));
 extern char *git_pathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 extern char *mkpathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /* Return a statically allocated filename matching the sha1 signature */
-extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern char *git_path_submodule(const char *path, const char *fmt, ...)
+extern const char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern const char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern const char *git_path_submodule(const char *path, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
+extern void report_linked_checkout_garbage(void);
 
 /*
  * Return the name of the file in the local object database that would
@@ -718,13 +737,13 @@ extern char *sha1_pack_name(const unsigned char *sha1);
 extern char *sha1_pack_index_name(const unsigned char *sha1);
 
 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
-extern const unsigned char null_sha1[20];
+extern const unsigned char null_sha1[GIT_SHA1_RAWSZ];
 
 static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 {
 	int i;
 
-	for (i = 0; i < 20; i++, sha1++, sha2++) {
+	for (i = 0; i < GIT_SHA1_RAWSZ; i++, sha1++, sha2++) {
 		if (*sha1 != *sha2)
 			return *sha1 - *sha2;
 	}
@@ -732,20 +751,42 @@ static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 	return 0;
 }
 
+static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
+{
+	return hashcmp(oid1->hash, oid2->hash);
+}
+
 static inline int is_null_sha1(const unsigned char *sha1)
 {
 	return !hashcmp(sha1, null_sha1);
 }
 
+static inline int is_null_oid(const struct object_id *oid)
+{
+	return !hashcmp(oid->hash, null_sha1);
+}
+
 static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
 {
-	memcpy(sha_dst, sha_src, 20);
+	memcpy(sha_dst, sha_src, GIT_SHA1_RAWSZ);
 }
+
+static inline void oidcpy(struct object_id *dst, const struct object_id *src)
+{
+	hashcpy(dst->hash, src->hash);
+}
+
 static inline void hashclr(unsigned char *hash)
 {
-	memset(hash, 0, 20);
+	memset(hash, 0, GIT_SHA1_RAWSZ);
+}
+
+static inline void oidclr(struct object_id *oid)
+{
+	hashclr(oid->hash);
 }
 
+
 #define EMPTY_TREE_SHA1_HEX \
 	"4b825dc642cb6eb9a060e54bf8d69288fbee4904"
 #define EMPTY_TREE_SHA1_BIN_LITERAL \
@@ -816,7 +857,6 @@ enum scld_error safe_create_leading_directories(char *path);
 enum scld_error safe_create_leading_directories_const(const char *path);
 
 int mkdir_in_gitdir(const char *path);
-extern void home_config_paths(char **global, char **xdg, char *file);
 extern char *expand_user_path(const char *path);
 const char *enter_repo(const char *path, int strict);
 static inline int is_absolute_path(const char *path)
@@ -836,8 +876,16 @@ char *strip_path_suffix(const char *path, const char *suffix);
 int daemon_avoid_alias(const char *path);
 extern int is_ntfs_dotgit(const char *name);
 
+/**
+ * Return a newly allocated string with the evaluation of
+ * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
+ * "$HOME/.config/git/$filename". Return NULL upon error.
+ */
+extern char *xdg_config_home(const char *filename);
+
 /* object replacement */
 #define LOOKUP_REPLACE_OBJECT 1
+#define LOOKUP_UNKNOWN_OBJECT 2
 extern void *read_sha1_file_extended(const unsigned char *sha1, enum object_type *type, unsigned long *size, unsigned flag);
 static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 {
@@ -874,6 +922,7 @@ static inline const unsigned char *lookup_replace_object_extended(const unsigned
 extern int sha1_object_info(const unsigned char *, unsigned long *);
 extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
 extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
+extern int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type, unsigned char *sha1, unsigned flags);
 extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
 extern int force_object_loose(const unsigned char *sha1, time_t mtime);
 extern int git_open_noatime(const char *name);
@@ -922,15 +971,21 @@ struct object_context {
 	unsigned char tree[20];
 	char path[PATH_MAX];
 	unsigned mode;
+	/*
+	 * symlink_path is only used by get_tree_entry_follow_symlinks,
+	 * and only for symlinks that point outside the repository.
+	 */
+	struct strbuf symlink_path;
 };
 
-#define GET_SHA1_QUIETLY        01
-#define GET_SHA1_COMMIT         02
-#define GET_SHA1_COMMITTISH     04
-#define GET_SHA1_TREE          010
-#define GET_SHA1_TREEISH       020
-#define GET_SHA1_BLOB	       040
-#define GET_SHA1_ONLY_TO_DIE 04000
+#define GET_SHA1_QUIETLY           01
+#define GET_SHA1_COMMIT            02
+#define GET_SHA1_COMMITTISH        04
+#define GET_SHA1_TREE             010
+#define GET_SHA1_TREEISH          020
+#define GET_SHA1_BLOB             040
+#define GET_SHA1_FOLLOW_SYMLINKS 0100
+#define GET_SHA1_ONLY_TO_DIE    04000
 
 extern int get_sha1(const char *str, unsigned char *sha1);
 extern int get_sha1_commit(const char *str, unsigned char *sha1);
@@ -952,8 +1007,10 @@ extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
  * null-terminated string.
  */
 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
+extern int get_oid_hex(const char *hex, struct object_id *sha1);
 
 extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
+extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */
 extern int read_ref_full(const char *refname, int resolve_flags,
 			 unsigned char *sha1, int *flags);
 extern int read_ref(const char *refname, unsigned char *sha1);
@@ -1174,6 +1231,7 @@ extern struct packed_git {
 	int pack_fd;
 	unsigned pack_local:1,
 		 pack_keep:1,
+		 freshened:1,
 		 do_not_close:1;
 	unsigned char sha1[20];
 	/* something like ".git/objects/pack/xxxxx.pack" */
@@ -1289,14 +1347,16 @@ int for_each_loose_file_in_objdir_buf(struct strbuf *path,
 
 /*
  * Iterate over loose and packed objects in both the local
- * repository and any alternates repositories.
+ * repository and any alternates repositories (unless the
+ * LOCAL_ONLY flag is set).
  */
+#define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
 typedef int each_packed_object_fn(const unsigned char *sha1,
 				  struct packed_git *pack,
 				  uint32_t pos,
 				  void *data);
-extern int for_each_loose_object(each_loose_object_fn, void *);
-extern int for_each_packed_object(each_packed_object_fn, void *);
+extern int for_each_loose_object(each_loose_object_fn, void *, unsigned flags);
+extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
 
 struct object_info {
 	/* Request */
@@ -1304,6 +1364,7 @@ struct object_info {
 	unsigned long *sizep;
 	unsigned long *disk_sizep;
 	unsigned char *delta_base_sha1;
+	struct strbuf *typename;
 
 	/* Response */
 	enum {
@@ -1492,9 +1553,13 @@ extern const char *git_mailmap_blob;
 extern void maybe_flush_or_die(FILE *, const char *);
 __attribute__((format (printf, 2, 3)))
 extern void fprintf_or_die(FILE *, const char *fmt, ...);
+
+#define COPY_READ_ERROR (-2)
+#define COPY_WRITE_ERROR (-3)
 extern int copy_fd(int ifd, int ofd);
 extern int copy_file(const char *dst, const char *src, int mode);
 extern int copy_file_with_time(const char *dst, const char *src, int mode);
+
 extern void write_or_die(int fd, const void *buf, size_t count);
 extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
 extern int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg);
@@ -1508,6 +1573,8 @@ static inline ssize_t write_str_in_full(int fd, const char *str)
 {
 	return write_in_full(fd, str, strlen(str));
 }
+__attribute__((format (printf, 3, 4)))
+extern int write_file(const char *path, int fatal, const char *fmt, ...);
 
 /* pager.c */
 extern void setup_pager(void);
diff --git a/combine-diff.c b/combine-diff.c
index 91edce58e1..8eb7278978 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -44,9 +44,9 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
 			memset(p->parent, 0,
 			       sizeof(p->parent[0]) * num_parent);
 
-			hashcpy(p->sha1, q->queue[i]->two->sha1);
+			hashcpy(p->oid.hash, q->queue[i]->two->sha1);
 			p->mode = q->queue[i]->two->mode;
-			hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
+			hashcpy(p->parent[n].oid.hash, q->queue[i]->one->sha1);
 			p->parent[n].mode = q->queue[i]->one->mode;
 			p->parent[n].status = q->queue[i]->status;
 			*tail = p;
@@ -77,7 +77,7 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
 			continue;
 		}
 
-		hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
+		hashcpy(p->parent[n].oid.hash, q->queue[i]->one->sha1);
 		p->parent[n].mode = q->queue[i]->one->mode;
 		p->parent[n].status = q->queue[i]->status;
 
@@ -284,7 +284,7 @@ static struct lline *coalesce_lines(struct lline *base, int *lenbase,
 	return base;
 }
 
-static char *grab_blob(const unsigned char *sha1, unsigned int mode,
+static char *grab_blob(const struct object_id *oid, unsigned int mode,
 		       unsigned long *size, struct userdiff_driver *textconv,
 		       const char *path)
 {
@@ -294,20 +294,20 @@ static char *grab_blob(const unsigned char *sha1, unsigned int mode,
 	if (S_ISGITLINK(mode)) {
 		blob = xmalloc(100);
 		*size = snprintf(blob, 100,
-				 "Subproject commit %s\n", sha1_to_hex(sha1));
-	} else if (is_null_sha1(sha1)) {
+				 "Subproject commit %s\n", oid_to_hex(oid));
+	} else if (is_null_oid(oid)) {
 		/* deleted blob */
 		*size = 0;
 		return xcalloc(1, 1);
 	} else if (textconv) {
 		struct diff_filespec *df = alloc_filespec(path);
-		fill_filespec(df, sha1, 1, mode);
+		fill_filespec(df, oid->hash, 1, mode);
 		*size = fill_textconv(textconv, df, &blob);
 		free_filespec(df);
 	} else {
-		blob = read_sha1_file(sha1, &type, size);
+		blob = read_sha1_file(oid->hash, &type, size);
 		if (type != OBJ_BLOB)
-			die("object '%s' is not a blob!", sha1_to_hex(sha1));
+			die("object '%s' is not a blob!", oid_to_hex(oid));
 	}
 	return blob;
 }
@@ -389,7 +389,7 @@ static void consume_line(void *state_, char *line, unsigned long len)
 	}
 }
 
-static void combine_diff(const unsigned char *parent, unsigned int mode,
+static void combine_diff(const struct object_id *parent, unsigned int mode,
 			 mmfile_t *result_file,
 			 struct sline *sline, unsigned int cnt, int n,
 			 int num_parent, int result_deleted,
@@ -897,7 +897,7 @@ static void show_combined_header(struct combine_diff_path *elem,
 				 int show_file_header)
 {
 	struct diff_options *opt = &rev->diffopt;
-	int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
+	int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
 	const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 	const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 	const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
@@ -914,11 +914,11 @@ static void show_combined_header(struct combine_diff_path *elem,
 			 "", elem->path, line_prefix, c_meta, c_reset);
 	printf("%s%sindex ", line_prefix, c_meta);
 	for (i = 0; i < num_parent; i++) {
-		abb = find_unique_abbrev(elem->parent[i].sha1,
+		abb = find_unique_abbrev(elem->parent[i].oid.hash,
 					 abbrev);
 		printf("%s%s", i ? "," : "", abb);
 	}
-	abb = find_unique_abbrev(elem->sha1, abbrev);
+	abb = find_unique_abbrev(elem->oid.hash, abbrev);
 	printf("..%s%s\n", abb, c_reset);
 
 	if (mode_differs) {
@@ -991,7 +991,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
 	/* Read the result of merge first */
 	if (!working_tree_file)
-		result = grab_blob(elem->sha1, elem->mode, &result_size,
+		result = grab_blob(&elem->oid, elem->mode, &result_size,
 				   textconv, elem->path);
 	else {
 		/* Used by diff-tree to read from the working tree */
@@ -1013,12 +1013,12 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 			result = strbuf_detach(&buf, NULL);
 			elem->mode = canon_mode(st.st_mode);
 		} else if (S_ISDIR(st.st_mode)) {
-			unsigned char sha1[20];
-			if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
-				result = grab_blob(elem->sha1, elem->mode,
+			struct object_id oid;
+			if (resolve_gitlink_ref(elem->path, "HEAD", oid.hash) < 0)
+				result = grab_blob(&elem->oid, elem->mode,
 						   &result_size, NULL, NULL);
 			else
-				result = grab_blob(sha1, elem->mode,
+				result = grab_blob(&oid, elem->mode,
 						   &result_size, NULL, NULL);
 		} else if (textconv) {
 			struct diff_filespec *df = alloc_filespec(elem->path);
@@ -1090,7 +1090,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 		for (i = 0; !is_binary && i < num_parent; i++) {
 			char *buf;
 			unsigned long size;
-			buf = grab_blob(elem->parent[i].sha1,
+			buf = grab_blob(&elem->parent[i].oid,
 					elem->parent[i].mode,
 					&size, NULL, NULL);
 			if (buffer_is_binary(buf, size))
@@ -1139,14 +1139,14 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	for (i = 0; i < num_parent; i++) {
 		int j;
 		for (j = 0; j < i; j++) {
-			if (!hashcmp(elem->parent[i].sha1,
-				     elem->parent[j].sha1)) {
+			if (!oidcmp(&elem->parent[i].oid,
+				     &elem->parent[j].oid)) {
 				reuse_combine_diff(sline, cnt, i, j);
 				break;
 			}
 		}
 		if (i <= j)
-			combine_diff(elem->parent[i].sha1,
+			combine_diff(&elem->parent[i].oid,
 				     elem->parent[i].mode,
 				     &result_file, sline,
 				     cnt, i, num_parent, result_deleted,
@@ -1206,9 +1206,9 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
 
 		/* Show sha1's */
 		for (i = 0; i < num_parent; i++)
-			printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
+			printf(" %s", diff_unique_abbrev(p->parent[i].oid.hash,
 							 opt->abbrev));
-		printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
+		printf(" %s ", diff_unique_abbrev(p->oid.hash, opt->abbrev));
 	}
 
 	if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
@@ -1271,16 +1271,16 @@ static struct diff_filepair *combined_pair(struct combine_diff_path *p,
 	for (i = 0; i < num_parent; i++) {
 		pair->one[i].path = p->path;
 		pair->one[i].mode = p->parent[i].mode;
-		hashcpy(pair->one[i].sha1, p->parent[i].sha1);
-		pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
+		hashcpy(pair->one[i].sha1, p->parent[i].oid.hash);
+		pair->one[i].sha1_valid = !is_null_oid(&p->parent[i].oid);
 		pair->one[i].has_more_entries = 1;
 	}
 	pair->one[num_parent - 1].has_more_entries = 0;
 
 	pair->two->path = p->path;
 	pair->two->mode = p->mode;
-	hashcpy(pair->two->sha1, p->sha1);
-	pair->two->sha1_valid = !is_null_sha1(p->sha1);
+	hashcpy(pair->two->sha1, p->oid.hash);
+	pair->two->sha1_valid = !is_null_oid(&p->oid);
 	return pair;
 }
 
diff --git a/command-list.txt b/command-list.txt
index f1eae0810d..b17c011bfd 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -1,29 +1,39 @@
-# List of known git commands.
-# command name				category [deprecated] [common]
-git-add                                 mainporcelain common
+# common commands are grouped by themes
+# these groups are output by 'git help' in the order declared here.
+# map each common command in the command list to one of these groups.
+### common groups (do not change this line)
+init         start a working area (see also: git help tutorial)
+worktree     work on the current change (see also: git help everyday)
+info         examine the history and state (see also: git help revisions)
+history      grow, mark and tweak your common history
+remote       collaborate (see also: git help workflows)
+
+### command list (do not change this line)
+# command name                          category [deprecated] [common]
+git-add                                 mainporcelain           worktree
 git-am                                  mainporcelain
 git-annotate                            ancillaryinterrogators
 git-apply                               plumbingmanipulators
 git-archimport                          foreignscminterface
 git-archive                             mainporcelain
-git-bisect                              mainporcelain common
+git-bisect                              mainporcelain           info
 git-blame                               ancillaryinterrogators
-git-branch                              mainporcelain common
+git-branch                              mainporcelain           history
 git-bundle                              mainporcelain
 git-cat-file                            plumbinginterrogators
 git-check-attr                          purehelpers
 git-check-ignore                        purehelpers
 git-check-mailmap                       purehelpers
-git-checkout                            mainporcelain common
+git-checkout                            mainporcelain           history
 git-checkout-index                      plumbingmanipulators
 git-check-ref-format                    purehelpers
 git-cherry                              ancillaryinterrogators
 git-cherry-pick                         mainporcelain
 git-citool                              mainporcelain
 git-clean                               mainporcelain
-git-clone                               mainporcelain common
+git-clone                               mainporcelain           init
 git-column                              purehelpers
-git-commit                              mainporcelain common
+git-commit                              mainporcelain           history
 git-commit-tree                         plumbingmanipulators
 git-config                              ancillarymanipulators
 git-count-objects                       ancillaryinterrogators
@@ -35,42 +45,42 @@ git-cvsimport                           foreignscminterface
 git-cvsserver                           foreignscminterface
 git-daemon                              synchingrepositories
 git-describe                            mainporcelain
-git-diff                                mainporcelain common
+git-diff                                mainporcelain           history
 git-diff-files                          plumbinginterrogators
 git-diff-index                          plumbinginterrogators
 git-diff-tree                           plumbinginterrogators
 git-difftool                            ancillaryinterrogators
-git-fast-export				ancillarymanipulators
-git-fast-import				ancillarymanipulators
-git-fetch                               mainporcelain common
+git-fast-export                         ancillarymanipulators
+git-fast-import                         ancillarymanipulators
+git-fetch                               mainporcelain           remote
 git-fetch-pack                          synchingrepositories
 git-filter-branch                       ancillarymanipulators
 git-fmt-merge-msg                       purehelpers
 git-for-each-ref                        plumbinginterrogators
 git-format-patch                        mainporcelain
-git-fsck	                        ancillaryinterrogators
+git-fsck                                ancillaryinterrogators
 git-gc                                  mainporcelain
 git-get-tar-commit-id                   ancillaryinterrogators
-git-grep                                mainporcelain common
+git-grep                                mainporcelain           info
 git-gui                                 mainporcelain
 git-hash-object                         plumbingmanipulators
-git-help				ancillaryinterrogators
+git-help                                ancillaryinterrogators
 git-http-backend                        synchingrepositories
 git-http-fetch                          synchelpers
 git-http-push                           synchelpers
 git-imap-send                           foreignscminterface
 git-index-pack                          plumbingmanipulators
-git-init                                mainporcelain common
+git-init                                mainporcelain           init
 git-instaweb                            ancillaryinterrogators
 git-interpret-trailers                  purehelpers
 gitk                                    mainporcelain
-git-log                                 mainporcelain common
+git-log                                 mainporcelain           info
 git-ls-files                            plumbinginterrogators
 git-ls-remote                           plumbinginterrogators
 git-ls-tree                             plumbinginterrogators
 git-mailinfo                            purehelpers
 git-mailsplit                           purehelpers
-git-merge                               mainporcelain common
+git-merge                               mainporcelain           history
 git-merge-base                          plumbinginterrogators
 git-merge-file                          plumbingmanipulators
 git-merge-index                         plumbingmanipulators
@@ -79,7 +89,7 @@ git-mergetool                           ancillarymanipulators
 git-merge-tree                          ancillaryinterrogators
 git-mktag                               plumbingmanipulators
 git-mktree                              plumbingmanipulators
-git-mv                                  mainporcelain common
+git-mv                                  mainporcelain           worktree
 git-name-rev                            plumbinginterrogators
 git-notes                               mainporcelain
 git-p4                                  foreignscminterface
@@ -90,11 +100,11 @@ git-parse-remote                        synchelpers
 git-patch-id                            purehelpers
 git-prune                               ancillarymanipulators
 git-prune-packed                        plumbingmanipulators
-git-pull                                mainporcelain common
-git-push                                mainporcelain common
+git-pull                                mainporcelain           remote
+git-push                                mainporcelain           remote
 git-quiltimport                         foreignscminterface
 git-read-tree                           plumbingmanipulators
-git-rebase                              mainporcelain common
+git-rebase                              mainporcelain           history
 git-receive-pack                        synchelpers
 git-reflog                              ancillarymanipulators
 git-relink                              ancillarymanipulators
@@ -103,28 +113,28 @@ git-repack                              ancillarymanipulators
 git-replace                             ancillarymanipulators
 git-request-pull                        foreignscminterface
 git-rerere                              ancillaryinterrogators
-git-reset                               mainporcelain common
+git-reset                               mainporcelain           worktree
 git-revert                              mainporcelain
 git-rev-list                            plumbinginterrogators
 git-rev-parse                           ancillaryinterrogators
-git-rm                                  mainporcelain common
+git-rm                                  mainporcelain           worktree
 git-send-email                          foreignscminterface
 git-send-pack                           synchingrepositories
 git-shell                               synchelpers
 git-shortlog                            mainporcelain
-git-show                                mainporcelain common
+git-show                                mainporcelain           info
 git-show-branch                         ancillaryinterrogators
 git-show-index                          plumbinginterrogators
 git-show-ref                            plumbinginterrogators
 git-sh-i18n                             purehelpers
 git-sh-setup                            purehelpers
 git-stash                               mainporcelain
-git-status                              mainporcelain common
+git-status                              mainporcelain           info
 git-stripspace                          purehelpers
 git-submodule                           mainporcelain
 git-svn                                 foreignscminterface
 git-symbolic-ref                        plumbingmanipulators
-git-tag                                 mainporcelain common
+git-tag                                 mainporcelain           history
 git-unpack-file                         plumbinginterrogators
 git-unpack-objects                      plumbingmanipulators
 git-update-index                        plumbingmanipulators
diff --git a/commit.c b/commit.c
index a8c7577d28..2d9de807ae 100644
--- a/commit.c
+++ b/commit.c
@@ -55,12 +55,12 @@ struct commit *lookup_commit(const unsigned char *sha1)
 
 struct commit *lookup_commit_reference_by_name(const char *name)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct commit *commit;
 
-	if (get_sha1_committish(name, sha1))
+	if (get_sha1_committish(name, oid.hash))
 		return NULL;
-	commit = lookup_commit_reference(sha1);
+	commit = lookup_commit_reference(oid.hash);
 	if (parse_commit(commit))
 		return NULL;
 	return commit;
@@ -99,7 +99,7 @@ static int commit_graft_alloc, commit_graft_nr;
 static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
 {
 	struct commit_graft **commit_graft_table = table;
-	return commit_graft_table[index]->sha1;
+	return commit_graft_table[index]->oid.hash;
 }
 
 static int commit_graft_pos(const unsigned char *sha1)
@@ -110,7 +110,7 @@ static int commit_graft_pos(const unsigned char *sha1)
 
 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 {
-	int pos = commit_graft_pos(graft->sha1);
+	int pos = commit_graft_pos(graft->oid.hash);
 
 	if (0 <= pos) {
 		if (ignore_dups)
@@ -138,22 +138,23 @@ struct commit_graft *read_graft_line(char *buf, int len)
 	/* The format is just "Commit Parent1 Parent2 ...\n" */
 	int i;
 	struct commit_graft *graft = NULL;
+	const int entry_size = GIT_SHA1_HEXSZ + 1;
 
 	while (len && isspace(buf[len-1]))
 		buf[--len] = '\0';
 	if (buf[0] == '#' || buf[0] == '\0')
 		return NULL;
-	if ((len + 1) % 41)
+	if ((len + 1) % entry_size)
 		goto bad_graft_data;
-	i = (len + 1) / 41 - 1;
-	graft = xmalloc(sizeof(*graft) + 20 * i);
+	i = (len + 1) / entry_size - 1;
+	graft = xmalloc(sizeof(*graft) + GIT_SHA1_RAWSZ * i);
 	graft->nr_parent = i;
-	if (get_sha1_hex(buf, graft->sha1))
+	if (get_oid_hex(buf, &graft->oid))
 		goto bad_graft_data;
-	for (i = 40; i < len; i += 41) {
+	for (i = GIT_SHA1_HEXSZ; i < len; i += entry_size) {
 		if (buf[i] != ' ')
 			goto bad_graft_data;
-		if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
+		if (get_sha1_hex(buf + i + 1, graft->parent[i/entry_size].hash))
 			goto bad_graft_data;
 	}
 	return graft;
@@ -302,39 +303,42 @@ int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long s
 {
 	const char *tail = buffer;
 	const char *bufptr = buffer;
-	unsigned char parent[20];
+	struct object_id parent;
 	struct commit_list **pptr;
 	struct commit_graft *graft;
+	const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
+	const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
 
 	if (item->object.parsed)
 		return 0;
 	item->object.parsed = 1;
 	tail += size;
-	if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
+	if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
+			bufptr[tree_entry_len] != '\n')
 		return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
-	if (get_sha1_hex(bufptr + 5, parent) < 0)
+	if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
 		return error("bad tree pointer in commit %s",
 			     sha1_to_hex(item->object.sha1));
-	item->tree = lookup_tree(parent);
-	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
+	item->tree = lookup_tree(parent.hash);
+	bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
 	pptr = &item->parents;
 
 	graft = lookup_commit_graft(item->object.sha1);
-	while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
+	while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
 		struct commit *new_parent;
 
-		if (tail <= bufptr + 48 ||
-		    get_sha1_hex(bufptr + 7, parent) ||
-		    bufptr[47] != '\n')
+		if (tail <= bufptr + parent_entry_len + 1 ||
+		    get_sha1_hex(bufptr + 7, parent.hash) ||
+		    bufptr[parent_entry_len] != '\n')
 			return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
-		bufptr += 48;
+		bufptr += parent_entry_len + 1;
 		/*
 		 * The clone is shallow if nr_parent < 0, and we must
 		 * not traverse its real parents even when we unhide them.
 		 */
 		if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
 			continue;
-		new_parent = lookup_commit(parent);
+		new_parent = lookup_commit(parent.hash);
 		if (new_parent)
 			pptr = &commit_list_insert(new_parent, pptr)->next;
 	}
@@ -342,7 +346,7 @@ int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long s
 		int i;
 		struct commit *new_parent;
 		for (i = 0; i < graft->nr_parent; i++) {
-			new_parent = lookup_commit(graft->parent[i]);
+			new_parent = lookup_commit(graft->parent[i].hash);
 			if (!new_parent)
 				continue;
 			pptr = &commit_list_insert(new_parent, pptr)->next;
@@ -1580,10 +1584,10 @@ struct commit *get_merge_parent(const char *name)
 {
 	struct object *obj;
 	struct commit *commit;
-	unsigned char sha1[20];
-	if (get_sha1(name, sha1))
+	struct object_id oid;
+	if (get_sha1(name, oid.hash))
 		return NULL;
-	obj = parse_object(sha1);
+	obj = parse_object(oid.hash);
 	commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 	if (commit && !commit->util) {
 		struct merge_remote_desc *desc;
diff --git a/commit.h b/commit.h
index 9f189cb054..ed3a1d59a5 100644
--- a/commit.h
+++ b/commit.h
@@ -226,9 +226,9 @@ enum rev_sort_order {
 void sort_in_topological_order(struct commit_list **, enum rev_sort_order);
 
 struct commit_graft {
-	unsigned char sha1[20];
+	struct object_id oid;
 	int nr_parent; /* < 0 if shallow commit */
-	unsigned char parent[FLEX_ARRAY][20]; /* more */
+	struct object_id parent[FLEX_ARRAY]; /* more */
 };
 typedef int (*each_commit_graft_fn)(const struct commit_graft *, void *);
 
diff --git a/compat/mingw.c b/compat/mingw.c
index 70f3191a4f..496e6f8bb0 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2128,3 +2128,14 @@ void mingw_startup()
 	/* initialize Unicode console */
 	winansi_init();
 }
+
+int uname(struct utsname *buf)
+{
+	DWORD v = GetVersion();
+	memset(buf, 0, sizeof(*buf));
+	strcpy(buf->sysname, "Windows");
+	sprintf(buf->release, "%u.%u", v & 0xff, (v >> 8) & 0xff);
+	/* assuming NT variants only.. */
+	sprintf(buf->version, "%u", (v >> 16) & 0x7fff);
+	return 0;
+}
diff --git a/compat/mingw.h b/compat/mingw.h
index 5e499cfb71..738865c6c0 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -76,6 +76,14 @@ struct itimerval {
 };
 #define ITIMER_REAL 0
 
+struct utsname {
+	char sysname[16];
+	char nodename[1];
+	char release[16];
+	char version[16];
+	char machine[1];
+};
+
 /*
  * sanitize preprocessor namespace polluted by Windows headers defining
  * macros which collide with git local versions
@@ -98,8 +106,6 @@ static inline unsigned int alarm(unsigned int seconds)
 { return 0; }
 static inline int fsync(int fd)
 { return _commit(fd); }
-static inline pid_t getppid(void)
-{ return 1; }
 static inline void sync(void)
 {}
 static inline uid_t getuid(void)
@@ -121,6 +127,12 @@ static inline int sigaddset(sigset_t *set, int signum)
 #define SIG_UNBLOCK 0
 static inline int sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
 { return 0; }
+static inline pid_t getppid(void)
+{ return 1; }
+static inline pid_t getpgid(pid_t pid)
+{ return pid == 0 ? getpid() : pid; }
+static inline pid_t tcgetpgrp(int fd)
+{ return getpid(); }
 
 /*
  * simple adaptors
@@ -171,6 +183,7 @@ struct passwd *getpwuid(uid_t uid);
 int setitimer(int type, struct itimerval *in, struct itimerval *out);
 int sigaction(int sig, struct sigaction *in, struct sigaction *out);
 int link(const char *oldpath, const char *newpath);
+int uname(struct utsname *buf);
 
 /*
  * replacements of existing functions
diff --git a/config.c b/config.c
index 66c0a51bce..ab46462e15 100644
--- a/config.c
+++ b/config.c
@@ -12,6 +12,7 @@
 #include "quote.h"
 #include "hashmap.h"
 #include "string-list.h"
+#include "utf8.h"
 
 struct config_source {
 	struct config_source *prev;
@@ -49,7 +50,7 @@ static struct config_set the_config_set;
 
 static int config_file_fgetc(struct config_source *conf)
 {
-	return fgetc(conf->u.file);
+	return getc_unlocked(conf->u.file);
 }
 
 static int config_file_ungetc(int c, struct config_source *conf)
@@ -417,8 +418,7 @@ static int git_parse_source(config_fn_t fn, void *data)
 	struct strbuf *var = &cf->var;
 
 	/* U+FEFF Byte Order Mark in UTF8 */
-	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
-	const unsigned char *bomptr = utf8_bom;
+	const char *bomptr = utf8_bom;
 
 	for (;;) {
 		int c = get_next_char();
@@ -426,7 +426,7 @@ static int git_parse_source(config_fn_t fn, void *data)
 			/* We are at the file beginning; skip UTF8-encoded BOM
 			 * if present. Sane editors won't put this in on their
 			 * own, but e.g. Windows Notepad will do it happily. */
-			if ((unsigned char) c == *bomptr) {
+			if (c == (*bomptr & 0377)) {
 				bomptr++;
 				continue;
 			} else {
@@ -1088,7 +1088,9 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 
 	f = fopen(filename, "r");
 	if (f) {
+		flockfile(f);
 		ret = do_config_from_file(fn, filename, filename, f, data);
+		funlockfile(f);
 		fclose(f);
 	}
 	return ret;
@@ -1185,10 +1187,8 @@ int git_config_system(void)
 int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 {
 	int ret = 0, found = 0;
-	char *xdg_config = NULL;
-	char *user_config = NULL;
-
-	home_config_paths(&user_config, &xdg_config, "config");
+	char *xdg_config = xdg_config_home("config");
+	char *user_config = expand_user_path("~/.gitconfig");
 
 	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0)) {
 		ret += git_config_from_file(fn, git_etc_gitconfig(),
diff --git a/config.mak.uname b/config.mak.uname
index f4e77cb9e5..d26665fa54 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -36,6 +36,7 @@ ifeq ($(uname_S),Linux)
 	HAVE_DEV_TTY = YesPlease
 	HAVE_CLOCK_GETTIME = YesPlease
 	HAVE_CLOCK_MONOTONIC = YesPlease
+	HAVE_GETDELIM = YesPlease
 endif
 ifeq ($(uname_S),GNU/kFreeBSD)
 	HAVE_ALLOCA_H = YesPlease
diff --git a/connect.c b/connect.c
index 391d21192f..c0144d859a 100644
--- a/connect.c
+++ b/connect.c
@@ -724,7 +724,7 @@ struct child_process *git_connect(int fd[2], const char *url,
 		conn->in = conn->out = -1;
 		if (protocol == PROTO_SSH) {
 			const char *ssh;
-			int putty;
+			int putty, tortoiseplink = 0;
 			char *ssh_host = hostandport;
 			const char *port = NULL;
 			get_host_and_port(&ssh_host, &port);
@@ -743,28 +743,40 @@ struct child_process *git_connect(int fd[2], const char *url,
 				free(path);
 				free(conn);
 				return NULL;
+			}
+
+			ssh = getenv("GIT_SSH_COMMAND");
+			if (ssh) {
+				conn->use_shell = 1;
+				putty = 0;
 			} else {
-				ssh = getenv("GIT_SSH_COMMAND");
-				if (ssh) {
-					conn->use_shell = 1;
-					putty = 0;
-				} else {
-					ssh = getenv("GIT_SSH");
-					if (!ssh)
-						ssh = "ssh";
-					putty = !!strcasestr(ssh, "plink");
-				}
-
-				argv_array_push(&conn->args, ssh);
-				if (putty && !strcasestr(ssh, "tortoiseplink"))
-					argv_array_push(&conn->args, "-batch");
-				if (port) {
-					/* P is for PuTTY, p is for OpenSSH */
-					argv_array_push(&conn->args, putty ? "-P" : "-p");
-					argv_array_push(&conn->args, port);
-				}
-				argv_array_push(&conn->args, ssh_host);
+				const char *base;
+				char *ssh_dup;
+
+				ssh = getenv("GIT_SSH");
+				if (!ssh)
+					ssh = "ssh";
+
+				ssh_dup = xstrdup(ssh);
+				base = basename(ssh_dup);
+
+				tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
+					!strcasecmp(base, "tortoiseplink.exe");
+				putty = !strcasecmp(base, "plink") ||
+					!strcasecmp(base, "plink.exe") || tortoiseplink;
+
+				free(ssh_dup);
+			}
+
+			argv_array_push(&conn->args, ssh);
+			if (tortoiseplink)
+				argv_array_push(&conn->args, "-batch");
+			if (port) {
+				/* P is for PuTTY, p is for OpenSSH */
+				argv_array_push(&conn->args, putty ? "-P" : "-p");
+				argv_array_push(&conn->args, port);
 			}
+			argv_array_push(&conn->args, ssh_host);
 		} else {
 			/* remove repo-local variables from the environment */
 			conn->env = local_repo_env;
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 5944c824ab..bfc74e9d57 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -665,8 +665,8 @@ __git_list_porcelain_commands ()
 		checkout-index)   : plumbing;;
 		commit-tree)      : plumbing;;
 		count-objects)    : infrequent;;
-		credential-cache) : credentials helper;;
-		credential-store) : credentials helper;;
+		credential)       : credentials;;
+		credential-*)     : credentials helper;;
 		cvsexportcommit)  : export;;
 		cvsimport)        : import;;
 		cvsserver)        : daemon;;
@@ -735,35 +735,29 @@ __git_list_porcelain_commands ()
 __git_porcelain_commands=
 __git_compute_porcelain_commands ()
 {
-	__git_compute_all_commands
 	test -n "$__git_porcelain_commands" ||
 	__git_porcelain_commands=$(__git_list_porcelain_commands)
 }
 
-__git_pretty_aliases ()
+# Lists all set config variables starting with the given section prefix,
+# with the prefix removed.
+__git_get_config_variables ()
 {
-	local i IFS=$'\n'
-	for i in $(git --git-dir="$(__gitdir)" config --get-regexp "pretty\..*" 2>/dev/null); do
-		case "$i" in
-		pretty.*)
-			i="${i#pretty.}"
-			echo "${i/ */}"
-			;;
-		esac
+	local section="$1" i IFS=$'\n'
+	for i in $(git --git-dir="$(__gitdir)" config --get-regexp "^$section\..*" 2>/dev/null); do
+		i="${i#$section.}"
+		echo "${i/ */}"
 	done
 }
 
+__git_pretty_aliases ()
+{
+	__git_get_config_variables "pretty"
+}
+
 __git_aliases ()
 {
-	local i IFS=$'\n'
-	for i in $(git --git-dir="$(__gitdir)" config --get-regexp "alias\..*" 2>/dev/null); do
-		case "$i" in
-		alias.*)
-			i="${i#alias.}"
-			echo "${i/ */}"
-			;;
-		esac
-	done
+	__git_get_config_variables "alias"
 }
 
 # __git_aliased_command requires 1 argument
@@ -1448,7 +1442,7 @@ _git_log ()
 		return
 		;;
 	--decorate=*)
-		__gitcomp "long short" "" "${cur##--decorate=}"
+		__gitcomp "full short no" "" "${cur##--decorate=}"
 		return
 		;;
 	--*)
@@ -2123,6 +2117,7 @@ _git_config ()
 		http.noEPSV
 		http.postBuffer
 		http.proxy
+		http.sslCipherList
 		http.sslCAInfo
 		http.sslCAPath
 		http.sslCert
@@ -2260,12 +2255,7 @@ _git_remote ()
 		__git_complete_remote_or_refspec
 		;;
 	update)
-		local i c='' IFS=$'\n'
-		for i in $(git --git-dir="$(__gitdir)" config --get-regexp "remotes\..*" 2>/dev/null); do
-			i="${i#remotes.}"
-			c="$c ${i/ */}"
-		done
-		__gitcomp "$c"
+		__gitcomp "$(__git_get_config_variables "remotes")"
 		;;
 	*)
 		;;
diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index fa1a5839af..07bd77c4c8 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -26,7 +26,7 @@ b,branch=     create a new branch from the split subtree
 ignore-joins  ignore prior --rejoin commits
 onto=         try connecting new tree to an existing one
 rejoin        merge the new branch back into HEAD
- options for 'add', 'merge', 'pull' and 'push'
+ options for 'add', 'merge', and 'pull'
 squash        merge subtree changes as a single commit
 "
 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
@@ -51,14 +51,21 @@ prefix=
 debug()
 {
 	if [ -n "$debug" ]; then
-		echo "$@" >&2
+		printf "%s\n" "$*" >&2
 	fi
 }
 
 say()
 {
 	if [ -z "$quiet" ]; then
-		echo "$@" >&2
+		printf "%s\n" "$*" >&2
+	fi
+}
+
+progress()
+{
+	if [ -z "$quiet" ]; then
+		printf "%s\r" "$*" >&2
 	fi
 }
 
@@ -599,7 +606,7 @@ cmd_split()
 	eval "$grl" |
 	while read rev parents; do
 		revcount=$(($revcount + 1))
-		say -n "$revcount/$revmax ($createcount)
"
+		progress "$revcount/$revmax ($createcount)"
 		debug "Processing commit: $rev"
 		exists=$(cache_get $rev)
 		if [ -n "$exists" ]; then
diff --git a/contrib/subtree/git-subtree.txt b/contrib/subtree/git-subtree.txt
index 54e4b4a243..60d76cdddf 100644
--- a/contrib/subtree/git-subtree.txt
+++ b/contrib/subtree/git-subtree.txt
@@ -146,7 +146,7 @@ OPTIONS
 OPTIONS FOR add, merge, push, pull
 ----------------------------------
 --squash::
-	This option is only valid for add, merge, push and pull
+	This option is only valid for add, merge, and pull
 	commands.
 +
 Instead of merging the entire history from the subtree project, produce
diff --git a/convert.c b/convert.c
index 9a5612e93d..f3bd3e93fb 100644
--- a/convert.c
+++ b/convert.c
@@ -356,9 +356,14 @@ static int filter_buffer_or_fd(int in, int out, void *data)
 	sigchain_push(SIGPIPE, SIG_IGN);
 
 	if (params->src) {
-		write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
+		write_err = (write_in_full(child_process.in,
+					   params->src, params->size) < 0);
+		if (errno == EPIPE)
+			write_err = 0;
 	} else {
 		write_err = copy_fd(params->fd, child_process.in);
+		if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
+			write_err = 0;
 	}
 
 	if (close(child_process.in))
diff --git a/copy.c b/copy.c
index f2970ec462..574fa1f09d 100644
--- a/copy.c
+++ b/copy.c
@@ -7,13 +7,10 @@ int copy_fd(int ifd, int ofd)
 		ssize_t len = xread(ifd, buffer, sizeof(buffer));
 		if (!len)
 			break;
-		if (len < 0) {
-			return error("copy-fd: read returned %s",
-				     strerror(errno));
-		}
+		if (len < 0)
+			return COPY_READ_ERROR;
 		if (write_in_full(ofd, buffer, len) < 0)
-			return error("copy-fd: write returned %s",
-				     strerror(errno));
+			return COPY_WRITE_ERROR;
 	}
 	return 0;
 }
@@ -43,6 +40,14 @@ int copy_file(const char *dst, const char *src, int mode)
 		return fdo;
 	}
 	status = copy_fd(fdi, fdo);
+	switch (status) {
+	case COPY_READ_ERROR:
+		error("copy-fd: read returned %s", strerror(errno));
+		break;
+	case COPY_WRITE_ERROR:
+		error("copy-fd: write returned %s", strerror(errno));
+		break;
+	}
 	close(fdi);
 	if (close(fdo) != 0)
 		return error("%s: close error: %s", dst, strerror(errno));
diff --git a/credential-store.c b/credential-store.c
index 925d3f4024..f6925096ff 100644
--- a/credential-store.c
+++ b/credential-store.c
@@ -6,7 +6,7 @@
 
 static struct lock_file credential_lock;
 
-static void parse_credential_file(const char *fn,
+static int parse_credential_file(const char *fn,
 				  struct credential *c,
 				  void (*match_cb)(struct credential *),
 				  void (*other_cb)(struct strbuf *))
@@ -14,18 +14,20 @@ static void parse_credential_file(const char *fn,
 	FILE *fh;
 	struct strbuf line = STRBUF_INIT;
 	struct credential entry = CREDENTIAL_INIT;
+	int found_credential = 0;
 
 	fh = fopen(fn, "r");
 	if (!fh) {
-		if (errno != ENOENT)
+		if (errno != ENOENT && errno != EACCES)
 			die_errno("unable to open %s", fn);
-		return;
+		return found_credential;
 	}
 
 	while (strbuf_getline(&line, fh, '\n') != EOF) {
 		credential_from_url(&entry, line.buf);
 		if (entry.username && entry.password &&
 		    credential_match(c, &entry)) {
+			found_credential = 1;
 			if (match_cb) {
 				match_cb(&entry);
 				break;
@@ -38,6 +40,7 @@ static void parse_credential_file(const char *fn,
 	credential_clear(&entry);
 	strbuf_release(&line);
 	fclose(fh);
+	return found_credential;
 }
 
 static void print_entry(struct credential *c)
@@ -64,21 +67,10 @@ static void rewrite_credential_file(const char *fn, struct credential *c,
 		die_errno("unable to commit credential store");
 }
 
-static void store_credential(const char *fn, struct credential *c)
+static void store_credential_file(const char *fn, struct credential *c)
 {
 	struct strbuf buf = STRBUF_INIT;
 
-	/*
-	 * Sanity check that what we are storing is actually sensible.
-	 * In particular, we can't make a URL without a protocol field.
-	 * Without either a host or pathname (depending on the scheme),
-	 * we have no primary key. And without a username and password,
-	 * we are not actually storing a credential.
-	 */
-	if (!c->protocol || !(c->host || c->path) ||
-	    !c->username || !c->password)
-		return;
-
 	strbuf_addf(&buf, "%s://", c->protocol);
 	strbuf_addstr_urlencode(&buf, c->username, 1);
 	strbuf_addch(&buf, ':');
@@ -95,8 +87,37 @@ static void store_credential(const char *fn, struct credential *c)
 	strbuf_release(&buf);
 }
 
-static void remove_credential(const char *fn, struct credential *c)
+static void store_credential(const struct string_list *fns, struct credential *c)
+{
+	struct string_list_item *fn;
+
+	/*
+	 * Sanity check that what we are storing is actually sensible.
+	 * In particular, we can't make a URL without a protocol field.
+	 * Without either a host or pathname (depending on the scheme),
+	 * we have no primary key. And without a username and password,
+	 * we are not actually storing a credential.
+	 */
+	if (!c->protocol || !(c->host || c->path) || !c->username || !c->password)
+		return;
+
+	for_each_string_list_item(fn, fns)
+		if (!access(fn->string, F_OK)) {
+			store_credential_file(fn->string, c);
+			return;
+		}
+	/*
+	 * Write credential to the filename specified by fns->items[0], thus
+	 * creating it
+	 */
+	if (fns->nr)
+		store_credential_file(fns->items[0].string, c);
+}
+
+static void remove_credential(const struct string_list *fns, struct credential *c)
 {
+	struct string_list_item *fn;
+
 	/*
 	 * Sanity check that we actually have something to match
 	 * against. The input we get is a restrictive pattern,
@@ -105,14 +126,20 @@ static void remove_credential(const char *fn, struct credential *c)
 	 * to empty input. So explicitly disallow it, and require that the
 	 * pattern have some actual content to match.
 	 */
-	if (c->protocol || c->host || c->path || c->username)
-		rewrite_credential_file(fn, c, NULL);
+	if (!c->protocol && !c->host && !c->path && !c->username)
+		return;
+	for_each_string_list_item(fn, fns)
+		if (!access(fn->string, F_OK))
+			rewrite_credential_file(fn->string, c, NULL);
 }
 
-static int lookup_credential(const char *fn, struct credential *c)
+static void lookup_credential(const struct string_list *fns, struct credential *c)
 {
-	parse_credential_file(fn, c, print_entry, NULL);
-	return c->username && c->password;
+	struct string_list_item *fn;
+
+	for_each_string_list_item(fn, fns)
+		if (parse_credential_file(fn->string, c, print_entry, NULL))
+			return; /* Found credential */
 }
 
 int main(int argc, char **argv)
@@ -123,6 +150,7 @@ int main(int argc, char **argv)
 	};
 	const char *op;
 	struct credential c = CREDENTIAL_INIT;
+	struct string_list fns = STRING_LIST_INIT_DUP;
 	char *file = NULL;
 	struct option options[] = {
 		OPT_STRING(0, "file", &file, "path",
@@ -137,22 +165,30 @@ int main(int argc, char **argv)
 		usage_with_options(usage, options);
 	op = argv[0];
 
-	if (!file)
-		file = expand_user_path("~/.git-credentials");
-	if (!file)
+	if (file) {
+		string_list_append(&fns, file);
+	} else {
+		if ((file = expand_user_path("~/.git-credentials")))
+			string_list_append_nodup(&fns, file);
+		file = xdg_config_home("credentials");
+		if (file)
+			string_list_append_nodup(&fns, file);
+	}
+	if (!fns.nr)
 		die("unable to set up default path; use --file");
 
 	if (credential_read(&c, stdin) < 0)
 		die("unable to read credential");
 
 	if (!strcmp(op, "get"))
-		lookup_credential(file, &c);
+		lookup_credential(&fns, &c);
 	else if (!strcmp(op, "erase"))
-		remove_credential(file, &c);
+		remove_credential(&fns, &c);
 	else if (!strcmp(op, "store"))
-		store_credential(file, &c);
+		store_credential(&fns, &c);
 	else
 		; /* Ignore unknown operation. */
 
+	string_list_clear(&fns, 0);
 	return 0;
 }
diff --git a/daemon.c b/daemon.c
index 9ee21877cd..d3d3e433e3 100644
--- a/daemon.c
+++ b/daemon.c
@@ -633,7 +633,7 @@ static void lookup_hostname(struct hostinfo *hi)
 		char **ap;
 		static char addrbuf[HOST_NAME_MAX + 1];
 
-		hent = gethostbyname(hostname.buf);
+		hent = gethostbyname(hi->hostname.buf);
 		if (hent) {
 			ap = hent->h_addr_list;
 			memset(&sa, 0, sizeof sa);
@@ -1166,15 +1166,6 @@ static struct credentials *prepare_credentials(const char *user_name,
 }
 #endif
 
-static void store_pid(const char *path)
-{
-	FILE *f = fopen(path, "w");
-	if (!f)
-		die_errno("cannot open pid file '%s'", path);
-	if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
-		die_errno("failed to write pid file '%s'", path);
-}
-
 static int serve(struct string_list *listen_addr, int listen_port,
     struct credentials *cred)
 {
@@ -1385,7 +1376,7 @@ int main(int argc, char **argv)
 		sanitize_stdfds();
 
 	if (pid_file)
-		store_pid(pid_file);
+		write_file(pid_file, 1, "%"PRIuMAX"\n", (uintmax_t) getpid());
 
 	/* prepare argv for serving-processes */
 	cld_argv = xmalloc(sizeof (char *) * (argc + 2));
diff --git a/date.c b/date.c
index 3eba2dfe88..733d1b29b1 100644
--- a/date.c
+++ b/date.c
@@ -704,10 +704,17 @@ int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
 		date += match;
 	}
 
-	/* mktime uses local timezone */
+	/* do not use mktime(), which uses local timezone, here */
 	*timestamp = tm_to_time_t(&tm);
+	if (*timestamp == -1)
+		return -1;
+
 	if (*offset == -1) {
-		time_t temp_time = mktime(&tm);
+		time_t temp_time;
+
+		/* gmtime_r() in match_digit() may have clobbered it */
+		tm.tm_isdst = -1;
+		temp_time = mktime(&tm);
 		if ((time_t)*timestamp > temp_time) {
 			*offset = ((time_t)*timestamp - temp_time) / 60;
 		} else {
@@ -715,9 +722,6 @@ int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
 		}
 	}
 
-	if (*timestamp == -1)
-		return -1;
-
 	if (!tm_gmt)
 		*timestamp -= *offset * 60;
 	return 0; /* success */
diff --git a/diff-lib.c b/diff-lib.c
index a85c4971ac..0d8c5358e4 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -125,7 +125,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			dpath->next = NULL;
 			memcpy(dpath->path, ce->name, path_len);
 			dpath->path[path_len] = '\0';
-			hashclr(dpath->sha1);
+			oidclr(&dpath->oid);
 			memset(&(dpath->parent[0]), 0,
 			       sizeof(struct combine_diff_parent)*5);
 
@@ -155,7 +155,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 				if (2 <= stage) {
 					int mode = nce->ce_mode;
 					num_compare_stages++;
-					hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
+					hashcpy(dpath->parent[stage-2].oid.hash, nce->sha1);
 					dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 					dpath->parent[stage-2].status =
 						DIFF_STATUS_MODIFIED;
@@ -212,6 +212,11 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 					       ce->sha1, !is_null_sha1(ce->sha1),
 					       ce->name, 0);
 				continue;
+			} else if (ce->ce_flags & CE_INTENT_TO_ADD) {
+				diff_addremove(&revs->diffopt, '+', ce->ce_mode,
+					       EMPTY_BLOB_SHA1_BIN, 0,
+					       ce->name, 0);
+				continue;
 			}
 
 			changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
@@ -339,14 +344,14 @@ static int show_modified(struct rev_info *revs,
 		memcpy(p->path, new->name, pathlen);
 		p->path[pathlen] = 0;
 		p->mode = mode;
-		hashclr(p->sha1);
+		oidclr(&p->oid);
 		memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 		p->parent[0].status = DIFF_STATUS_MODIFIED;
 		p->parent[0].mode = new->ce_mode;
-		hashcpy(p->parent[0].sha1, new->sha1);
+		hashcpy(p->parent[0].oid.hash, new->sha1);
 		p->parent[1].status = DIFF_STATUS_MODIFIED;
 		p->parent[1].mode = old->ce_mode;
-		hashcpy(p->parent[1].sha1, old->sha1);
+		hashcpy(p->parent[1].oid.hash, old->sha1);
 		show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 		free(p);
 		return 0;
@@ -376,6 +381,13 @@ static void do_oneway_diff(struct unpack_trees_options *o,
 	struct rev_info *revs = o->unpack_data;
 	int match_missing, cached;
 
+	/* i-t-a entries do not actually exist in the index */
+	if (idx && (idx->ce_flags & CE_INTENT_TO_ADD)) {
+		idx = NULL;
+		if (!tree)
+			return;	/* nothing to diff.. */
+	}
+
 	/* if the entry is not checked out, don't examine work tree */
 	cached = o->index_only ||
 		(idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
diff --git a/diff-no-index.c b/diff-no-index.c
index 265709ba8c..0320605a84 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -97,8 +97,27 @@ static int queue_diff(struct diff_options *o,
 	if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
 		return -1;
 
-	if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
-		return error("file/directory conflict: %s, %s", name1, name2);
+	if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2)) {
+		struct diff_filespec *d1, *d2;
+
+		if (S_ISDIR(mode1)) {
+			/* 2 is file that is created */
+			d1 = noindex_filespec(NULL, 0);
+			d2 = noindex_filespec(name2, mode2);
+			name2 = NULL;
+			mode2 = 0;
+		} else {
+			/* 1 is file that is deleted */
+			d1 = noindex_filespec(name1, mode1);
+			d2 = noindex_filespec(NULL, 0);
+			name1 = NULL;
+			mode1 = 0;
+		}
+		/* emit that file */
+		diff_queue(&diff_queued_diff, d1, d2);
+
+		/* and then let the entire directory be created or deleted */
+	}
 
 	if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
 		struct strbuf buffer1 = STRBUF_INIT;
@@ -182,12 +201,50 @@ static int queue_diff(struct diff_options *o,
 	}
 }
 
+/* append basename of F to D */
+static void append_basename(struct strbuf *path, const char *dir, const char *file)
+{
+	const char *tail = strrchr(file, '/');
+
+	strbuf_addstr(path, dir);
+	while (path->len && path->buf[path->len - 1] == '/')
+		path->len--;
+	strbuf_addch(path, '/');
+	strbuf_addstr(path, tail ? tail + 1 : file);
+}
+
+/*
+ * DWIM "diff D F" into "diff D/F F" and "diff F D" into "diff F D/F"
+ * Note that we append the basename of F to D/, so "diff a/b/file D"
+ * becomes "diff a/b/file D/file", not "diff a/b/file D/a/b/file".
+ */
+static void fixup_paths(const char **path, struct strbuf *replacement)
+{
+	unsigned int isdir0, isdir1;
+
+	if (path[0] == file_from_standard_input ||
+	    path[1] == file_from_standard_input)
+		return;
+	isdir0 = is_directory(path[0]);
+	isdir1 = is_directory(path[1]);
+	if (isdir0 == isdir1)
+		return;
+	if (isdir0) {
+		append_basename(replacement, path[0], path[1]);
+		path[0] = replacement->buf;
+	} else {
+		append_basename(replacement, path[1], path[0]);
+		path[1] = replacement->buf;
+	}
+}
+
 void diff_no_index(struct rev_info *revs,
 		   int argc, const char **argv,
 		   const char *prefix)
 {
 	int i, prefixlen;
 	const char *paths[2];
+	struct strbuf replacement = STRBUF_INIT;
 
 	diff_setup(&revs->diffopt);
 	for (i = 1; i < argc - 2; ) {
@@ -217,6 +274,9 @@ void diff_no_index(struct rev_info *revs,
 			p = xstrdup(prefix_filename(prefix, prefixlen, p));
 		paths[i] = p;
 	}
+
+	fixup_paths(paths, &replacement);
+
 	revs->diffopt.skip_stat_unmatch = 1;
 	if (!revs->diffopt.output_format)
 		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
@@ -235,6 +295,8 @@ void diff_no_index(struct rev_info *revs,
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
 
+	strbuf_release(&replacement);
+
 	/*
 	 * The return code for --no-index imitates diff(1):
 	 * 0 = no changes, 1 = changes, else error
diff --git a/diff.h b/diff.h
index b4a624d235..f6fdf49e14 100644
--- a/diff.h
+++ b/diff.h
@@ -6,6 +6,7 @@
 
 #include "tree-walk.h"
 #include "pathspec.h"
+#include "object.h"
 
 struct rev_info;
 struct diff_options;
@@ -207,11 +208,11 @@ struct combine_diff_path {
 	struct combine_diff_path *next;
 	char *path;
 	unsigned int mode;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct combine_diff_parent {
 		char status;
 		unsigned int mode;
-		unsigned char sha1[20];
+		struct object_id oid;
 	} parent[FLEX_ARRAY];
 };
 #define combine_diff_path_size(n, l) \
diff --git a/dir.c b/dir.c
index 0943a81964..8209f8b8af 100644
--- a/dir.c
+++ b/dir.c
@@ -12,6 +12,9 @@
 #include "refs.h"
 #include "wildmatch.h"
 #include "pathspec.h"
+#include "utf8.h"
+#include "varint.h"
+#include "ewah/ewok.h"
 
 struct path_simplify {
 	int len;
@@ -31,8 +34,22 @@ enum path_treatment {
 	path_untracked
 };
 
+/*
+ * Support data structure for our opendir/readdir/closedir wrappers
+ */
+struct cached_dir {
+	DIR *fdir;
+	struct untracked_cache_dir *untracked;
+	int nr_files;
+	int nr_dirs;
+
+	struct dirent *de;
+	const char *file;
+	struct untracked_cache_dir *ucd;
+};
+
 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
-	const char *path, int len,
+	const char *path, int len, struct untracked_cache_dir *untracked,
 	int check_only, const struct path_simplify *simplify);
 static int get_dtype(struct dirent *de, const char *path, int len);
 
@@ -384,7 +401,6 @@ int report_path_error(const char *ps_matched,
 	/*
 	 * Make sure all pathspec matched; otherwise it is an error.
 	 */
-	struct strbuf sb = STRBUF_INIT;
 	int num, errors = 0;
 	for (num = 0; num < pathspec->nr; num++) {
 		int other, found_dup;
@@ -416,7 +432,6 @@ int report_path_error(const char *ps_matched,
 		      pathspec->items[num].original);
 		errors++;
 	}
-	strbuf_release(&sb);
 	return errors;
 }
 
@@ -509,7 +524,8 @@ void add_exclude(const char *string, const char *base,
 	x->el = el;
 }
 
-static void *read_skip_worktree_file_from_index(const char *path, size_t *size)
+static void *read_skip_worktree_file_from_index(const char *path, size_t *size,
+						struct sha1_stat *sha1_stat)
 {
 	int pos, len;
 	unsigned long sz;
@@ -528,6 +544,10 @@ static void *read_skip_worktree_file_from_index(const char *path, size_t *size)
 		return NULL;
 	}
 	*size = xsize_t(sz);
+	if (sha1_stat) {
+		memset(&sha1_stat->stat, 0, sizeof(sha1_stat->stat));
+		hashcpy(sha1_stat->sha1, active_cache[pos]->sha1);
+	}
 	return data;
 }
 
@@ -572,11 +592,93 @@ static void trim_trailing_spaces(char *buf)
 		*last_space = '\0';
 }
 
-int add_excludes_from_file_to_list(const char *fname,
-				   const char *base,
-				   int baselen,
-				   struct exclude_list *el,
-				   int check_index)
+/*
+ * Given a subdirectory name and "dir" of the current directory,
+ * search the subdir in "dir" and return it, or create a new one if it
+ * does not exist in "dir".
+ *
+ * If "name" has the trailing slash, it'll be excluded in the search.
+ */
+static struct untracked_cache_dir *lookup_untracked(struct untracked_cache *uc,
+						    struct untracked_cache_dir *dir,
+						    const char *name, int len)
+{
+	int first, last;
+	struct untracked_cache_dir *d;
+	if (!dir)
+		return NULL;
+	if (len && name[len - 1] == '/')
+		len--;
+	first = 0;
+	last = dir->dirs_nr;
+	while (last > first) {
+		int cmp, next = (last + first) >> 1;
+		d = dir->dirs[next];
+		cmp = strncmp(name, d->name, len);
+		if (!cmp && strlen(d->name) > len)
+			cmp = -1;
+		if (!cmp)
+			return d;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+
+	uc->dir_created++;
+	d = xmalloc(sizeof(*d) + len + 1);
+	memset(d, 0, sizeof(*d));
+	memcpy(d->name, name, len);
+	d->name[len] = '\0';
+
+	ALLOC_GROW(dir->dirs, dir->dirs_nr + 1, dir->dirs_alloc);
+	memmove(dir->dirs + first + 1, dir->dirs + first,
+		(dir->dirs_nr - first) * sizeof(*dir->dirs));
+	dir->dirs_nr++;
+	dir->dirs[first] = d;
+	return d;
+}
+
+static void do_invalidate_gitignore(struct untracked_cache_dir *dir)
+{
+	int i;
+	dir->valid = 0;
+	dir->untracked_nr = 0;
+	for (i = 0; i < dir->dirs_nr; i++)
+		do_invalidate_gitignore(dir->dirs[i]);
+}
+
+static void invalidate_gitignore(struct untracked_cache *uc,
+				 struct untracked_cache_dir *dir)
+{
+	uc->gitignore_invalidated++;
+	do_invalidate_gitignore(dir);
+}
+
+static void invalidate_directory(struct untracked_cache *uc,
+				 struct untracked_cache_dir *dir)
+{
+	int i;
+	uc->dir_invalidated++;
+	dir->valid = 0;
+	dir->untracked_nr = 0;
+	for (i = 0; i < dir->dirs_nr; i++)
+		dir->dirs[i]->recurse = 0;
+}
+
+/*
+ * Given a file with name "fname", read it (either from disk, or from
+ * the index if "check_index" is non-zero), parse it and store the
+ * exclude rules in "el".
+ *
+ * If "ss" is not NULL, compute SHA-1 of the exclude file and fill
+ * stat data from disk (only valid if add_excludes returns zero). If
+ * ss_valid is non-zero, "ss" must contain good value as input.
+ */
+static int add_excludes(const char *fname, const char *base, int baselen,
+			struct exclude_list *el, int check_index,
+			struct sha1_stat *sha1_stat)
 {
 	struct stat st;
 	int fd, i, lineno = 1;
@@ -590,7 +692,7 @@ int add_excludes_from_file_to_list(const char *fname,
 		if (0 <= fd)
 			close(fd);
 		if (!check_index ||
-		    (buf = read_skip_worktree_file_from_index(fname, &size)) == NULL)
+		    (buf = read_skip_worktree_file_from_index(fname, &size, sha1_stat)) == NULL)
 			return -1;
 		if (size == 0) {
 			free(buf);
@@ -603,6 +705,11 @@ int add_excludes_from_file_to_list(const char *fname,
 	} else {
 		size = xsize_t(st.st_size);
 		if (size == 0) {
+			if (sha1_stat) {
+				fill_stat_data(&sha1_stat->stat, &st);
+				hashcpy(sha1_stat->sha1, EMPTY_BLOB_SHA1_BIN);
+				sha1_stat->valid = 1;
+			}
 			close(fd);
 			return 0;
 		}
@@ -614,10 +721,31 @@ int add_excludes_from_file_to_list(const char *fname,
 		}
 		buf[size++] = '\n';
 		close(fd);
+		if (sha1_stat) {
+			int pos;
+			if (sha1_stat->valid &&
+			    !match_stat_data_racy(&the_index, &sha1_stat->stat, &st))
+				; /* no content change, ss->sha1 still good */
+			else if (check_index &&
+				 (pos = cache_name_pos(fname, strlen(fname))) >= 0 &&
+				 !ce_stage(active_cache[pos]) &&
+				 ce_uptodate(active_cache[pos]) &&
+				 !would_convert_to_git(fname))
+				hashcpy(sha1_stat->sha1, active_cache[pos]->sha1);
+			else
+				hash_sha1_file(buf, size, "blob", sha1_stat->sha1);
+			fill_stat_data(&sha1_stat->stat, &st);
+			sha1_stat->valid = 1;
+		}
 	}
 
 	el->filebuf = buf;
+
+	if (skip_utf8_bom(&buf, size))
+		size -= buf - el->filebuf;
+
 	entry = buf;
+
 	for (i = 0; i < size; i++) {
 		if (buf[i] == '\n') {
 			if (entry != buf + i && entry[0] != '#') {
@@ -632,6 +760,13 @@ int add_excludes_from_file_to_list(const char *fname,
 	return 0;
 }
 
+int add_excludes_from_file_to_list(const char *fname, const char *base,
+				   int baselen, struct exclude_list *el,
+				   int check_index)
+{
+	return add_excludes(fname, base, baselen, el, check_index, NULL);
+}
+
 struct exclude_list *add_exclude_list(struct dir_struct *dir,
 				      int group_type, const char *src)
 {
@@ -649,14 +784,28 @@ struct exclude_list *add_exclude_list(struct dir_struct *dir,
 /*
  * Used to set up core.excludesfile and .git/info/exclude lists.
  */
-void add_excludes_from_file(struct dir_struct *dir, const char *fname)
+static void add_excludes_from_file_1(struct dir_struct *dir, const char *fname,
+				     struct sha1_stat *sha1_stat)
 {
 	struct exclude_list *el;
+	/*
+	 * catch setup_standard_excludes() that's called before
+	 * dir->untracked is assigned. That function behaves
+	 * differently when dir->untracked is non-NULL.
+	 */
+	if (!dir->untracked)
+		dir->unmanaged_exclude_files++;
 	el = add_exclude_list(dir, EXC_FILE, fname);
-	if (add_excludes_from_file_to_list(fname, "", 0, el, 0) < 0)
+	if (add_excludes(fname, "", 0, el, 0, sha1_stat) < 0)
 		die("cannot use %s as an exclude file", fname);
 }
 
+void add_excludes_from_file(struct dir_struct *dir, const char *fname)
+{
+	dir->unmanaged_exclude_files++; /* see validate_untracked_cache() */
+	add_excludes_from_file_1(dir, fname, NULL);
+}
+
 int match_basename(const char *basename, int basenamelen,
 		   const char *pattern, int prefix, int patternlen,
 		   int flags)
@@ -831,6 +980,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 	struct exclude_list_group *group;
 	struct exclude_list *el;
 	struct exclude_stack *stk = NULL;
+	struct untracked_cache_dir *untracked;
 	int current;
 
 	group = &dir->exclude_list_group[EXC_DIRS];
@@ -868,8 +1018,14 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 	/* Read from the parent directories and push them down. */
 	current = stk ? stk->baselen : -1;
 	strbuf_setlen(&dir->basebuf, current < 0 ? 0 : current);
+	if (dir->untracked)
+		untracked = stk ? stk->ucd : dir->untracked->root;
+	else
+		untracked = NULL;
+
 	while (current < baselen) {
 		const char *cp;
+		struct sha1_stat sha1_stat;
 
 		stk = xcalloc(1, sizeof(*stk));
 		if (current < 0) {
@@ -880,10 +1036,15 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 			if (!cp)
 				die("oops in prep_exclude");
 			cp++;
+			untracked =
+				lookup_untracked(dir->untracked, untracked,
+						 base + current,
+						 cp - base - current);
 		}
 		stk->prev = dir->exclude_stack;
 		stk->baselen = cp - base;
 		stk->exclude_ix = group->nr;
+		stk->ucd = untracked;
 		el = add_exclude_list(dir, EXC_DIRS, NULL);
 		strbuf_add(&dir->basebuf, base + current, stk->baselen - current);
 		assert(stk->baselen == dir->basebuf.len);
@@ -906,7 +1067,23 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 		}
 
 		/* Try to read per-directory file */
-		if (dir->exclude_per_dir) {
+		hashclr(sha1_stat.sha1);
+		sha1_stat.valid = 0;
+		if (dir->exclude_per_dir &&
+		    /*
+		     * If we know that no files have been added in
+		     * this directory (i.e. valid_cached_dir() has
+		     * been executed and set untracked->valid) ..
+		     */
+		    (!untracked || !untracked->valid ||
+		     /*
+		      * .. and .gitignore does not exist before
+		      * (i.e. null exclude_sha1 and skip_worktree is
+		      * not set). Then we can skip loading .gitignore,
+		      * which would result in ENOENT anyway.
+		      * skip_worktree is taken care in read_directory()
+		      */
+		     !is_null_sha1(untracked->exclude_sha1))) {
 			/*
 			 * dir->basebuf gets reused by the traversal, but we
 			 * need fname to remain unchanged to ensure the src
@@ -919,8 +1096,27 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 			strbuf_addbuf(&sb, &dir->basebuf);
 			strbuf_addstr(&sb, dir->exclude_per_dir);
 			el->src = strbuf_detach(&sb, NULL);
-			add_excludes_from_file_to_list(el->src, el->src,
-						       stk->baselen, el, 1);
+			add_excludes(el->src, el->src, stk->baselen, el, 1,
+				     untracked ? &sha1_stat : NULL);
+		}
+		/*
+		 * NEEDSWORK: when untracked cache is enabled, prep_exclude()
+		 * will first be called in valid_cached_dir() then maybe many
+		 * times more in last_exclude_matching(). When the cache is
+		 * used, last_exclude_matching() will not be called and
+		 * reading .gitignore content will be a waste.
+		 *
+		 * So when it's called by valid_cached_dir() and we can get
+		 * .gitignore SHA-1 from the index (i.e. .gitignore is not
+		 * modified on work tree), we could delay reading the
+		 * .gitignore content until we absolutely need it in
+		 * last_exclude_matching(). Be careful about ignore rule
+		 * order, though, if you do that.
+		 */
+		if (untracked &&
+		    hashcmp(sha1_stat.sha1, untracked->exclude_sha1)) {
+			invalidate_gitignore(dir->untracked, untracked);
+			hashcpy(untracked->exclude_sha1, sha1_stat.sha1);
 		}
 		dir->exclude_stack = stk;
 		current = stk->baselen;
@@ -1101,6 +1297,7 @@ static enum exist_status directory_exists_in_index(const char *dirname, int len)
  *  (c) otherwise, we recurse into it.
  */
 static enum path_treatment treat_directory(struct dir_struct *dir,
+	struct untracked_cache_dir *untracked,
 	const char *dirname, int len, int exclude,
 	const struct path_simplify *simplify)
 {
@@ -1128,7 +1325,9 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 	if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
 		return exclude ? path_excluded : path_untracked;
 
-	return read_directory_recursive(dir, dirname, len, 1, simplify);
+	untracked = lookup_untracked(dir->untracked, untracked, dirname, len);
+	return read_directory_recursive(dir, dirname, len,
+					untracked, 1, simplify);
 }
 
 /*
@@ -1244,6 +1443,7 @@ static int get_dtype(struct dirent *de, const char *path, int len)
 }
 
 static enum path_treatment treat_one_path(struct dir_struct *dir,
+					  struct untracked_cache_dir *untracked,
 					  struct strbuf *path,
 					  const struct path_simplify *simplify,
 					  int dtype, struct dirent *de)
@@ -1296,7 +1496,7 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
 		return path_none;
 	case DT_DIR:
 		strbuf_addch(path, '/');
-		return treat_directory(dir, path->buf, path->len, exclude,
+		return treat_directory(dir, untracked, path->buf, path->len, exclude,
 			simplify);
 	case DT_REG:
 	case DT_LNK:
@@ -1304,14 +1504,52 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
 	}
 }
 
+static enum path_treatment treat_path_fast(struct dir_struct *dir,
+					   struct untracked_cache_dir *untracked,
+					   struct cached_dir *cdir,
+					   struct strbuf *path,
+					   int baselen,
+					   const struct path_simplify *simplify)
+{
+	strbuf_setlen(path, baselen);
+	if (!cdir->ucd) {
+		strbuf_addstr(path, cdir->file);
+		return path_untracked;
+	}
+	strbuf_addstr(path, cdir->ucd->name);
+	/* treat_one_path() does this before it calls treat_directory() */
+	if (path->buf[path->len - 1] != '/')
+		strbuf_addch(path, '/');
+	if (cdir->ucd->check_only)
+		/*
+		 * check_only is set as a result of treat_directory() getting
+		 * to its bottom. Verify again the same set of directories
+		 * with check_only set.
+		 */
+		return read_directory_recursive(dir, path->buf, path->len,
+						cdir->ucd, 1, simplify);
+	/*
+	 * We get path_recurse in the first run when
+	 * directory_exists_in_index() returns index_nonexistent. We
+	 * are sure that new changes in the index does not impact the
+	 * outcome. Return now.
+	 */
+	return path_recurse;
+}
+
 static enum path_treatment treat_path(struct dir_struct *dir,
-				      struct dirent *de,
+				      struct untracked_cache_dir *untracked,
+				      struct cached_dir *cdir,
 				      struct strbuf *path,
 				      int baselen,
 				      const struct path_simplify *simplify)
 {
 	int dtype;
+	struct dirent *de = cdir->de;
 
+	if (!de)
+		return treat_path_fast(dir, untracked, cdir, path,
+				       baselen, simplify);
 	if (is_dot_or_dotdot(de->d_name) || !strcmp(de->d_name, ".git"))
 		return path_none;
 	strbuf_setlen(path, baselen);
@@ -1320,7 +1558,121 @@ static enum path_treatment treat_path(struct dir_struct *dir,
 		return path_none;
 
 	dtype = DTYPE(de);
-	return treat_one_path(dir, path, simplify, dtype, de);
+	return treat_one_path(dir, untracked, path, simplify, dtype, de);
+}
+
+static void add_untracked(struct untracked_cache_dir *dir, const char *name)
+{
+	if (!dir)
+		return;
+	ALLOC_GROW(dir->untracked, dir->untracked_nr + 1,
+		   dir->untracked_alloc);
+	dir->untracked[dir->untracked_nr++] = xstrdup(name);
+}
+
+static int valid_cached_dir(struct dir_struct *dir,
+			    struct untracked_cache_dir *untracked,
+			    struct strbuf *path,
+			    int check_only)
+{
+	struct stat st;
+
+	if (!untracked)
+		return 0;
+
+	if (stat(path->len ? path->buf : ".", &st)) {
+		invalidate_directory(dir->untracked, untracked);
+		memset(&untracked->stat_data, 0, sizeof(untracked->stat_data));
+		return 0;
+	}
+	if (!untracked->valid ||
+	    match_stat_data_racy(&the_index, &untracked->stat_data, &st)) {
+		if (untracked->valid)
+			invalidate_directory(dir->untracked, untracked);
+		fill_stat_data(&untracked->stat_data, &st);
+		return 0;
+	}
+
+	if (untracked->check_only != !!check_only) {
+		invalidate_directory(dir->untracked, untracked);
+		return 0;
+	}
+
+	/*
+	 * prep_exclude will be called eventually on this directory,
+	 * but it's called much later in last_exclude_matching(). We
+	 * need it now to determine the validity of the cache for this
+	 * path. The next calls will be nearly no-op, the way
+	 * prep_exclude() is designed.
+	 */
+	if (path->len && path->buf[path->len - 1] != '/') {
+		strbuf_addch(path, '/');
+		prep_exclude(dir, path->buf, path->len);
+		strbuf_setlen(path, path->len - 1);
+	} else
+		prep_exclude(dir, path->buf, path->len);
+
+	/* hopefully prep_exclude() haven't invalidated this entry... */
+	return untracked->valid;
+}
+
+static int open_cached_dir(struct cached_dir *cdir,
+			   struct dir_struct *dir,
+			   struct untracked_cache_dir *untracked,
+			   struct strbuf *path,
+			   int check_only)
+{
+	memset(cdir, 0, sizeof(*cdir));
+	cdir->untracked = untracked;
+	if (valid_cached_dir(dir, untracked, path, check_only))
+		return 0;
+	cdir->fdir = opendir(path->len ? path->buf : ".");
+	if (dir->untracked)
+		dir->untracked->dir_opened++;
+	if (!cdir->fdir)
+		return -1;
+	return 0;
+}
+
+static int read_cached_dir(struct cached_dir *cdir)
+{
+	if (cdir->fdir) {
+		cdir->de = readdir(cdir->fdir);
+		if (!cdir->de)
+			return -1;
+		return 0;
+	}
+	while (cdir->nr_dirs < cdir->untracked->dirs_nr) {
+		struct untracked_cache_dir *d = cdir->untracked->dirs[cdir->nr_dirs];
+		if (!d->recurse) {
+			cdir->nr_dirs++;
+			continue;
+		}
+		cdir->ucd = d;
+		cdir->nr_dirs++;
+		return 0;
+	}
+	cdir->ucd = NULL;
+	if (cdir->nr_files < cdir->untracked->untracked_nr) {
+		struct untracked_cache_dir *d = cdir->untracked;
+		cdir->file = d->untracked[cdir->nr_files++];
+		return 0;
+	}
+	return -1;
+}
+
+static void close_cached_dir(struct cached_dir *cdir)
+{
+	if (cdir->fdir)
+		closedir(cdir->fdir);
+	/*
+	 * We have gone through this directory and found no untracked
+	 * entries. Mark it valid.
+	 */
+	if (cdir->untracked) {
+		cdir->untracked->valid = 1;
+		cdir->untracked->recurse = 1;
+	}
 }
 
 /*
@@ -1336,38 +1688,48 @@ static enum path_treatment treat_path(struct dir_struct *dir,
  */
 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 				    const char *base, int baselen,
-				    int check_only,
+				    struct untracked_cache_dir *untracked, int check_only,
 				    const struct path_simplify *simplify)
 {
-	DIR *fdir;
+	struct cached_dir cdir;
 	enum path_treatment state, subdir_state, dir_state = path_none;
-	struct dirent *de;
 	struct strbuf path = STRBUF_INIT;
 
 	strbuf_add(&path, base, baselen);
 
-	fdir = opendir(path.len ? path.buf : ".");
-	if (!fdir)
+	if (open_cached_dir(&cdir, dir, untracked, &path, check_only))
 		goto out;
 
-	while ((de = readdir(fdir)) != NULL) {
+	if (untracked)
+		untracked->check_only = !!check_only;
+
+	while (!read_cached_dir(&cdir)) {
 		/* check how the file or directory should be treated */
-		state = treat_path(dir, de, &path, baselen, simplify);
+		state = treat_path(dir, untracked, &cdir, &path, baselen, simplify);
+
 		if (state > dir_state)
 			dir_state = state;
 
 		/* recurse into subdir if instructed by treat_path */
 		if (state == path_recurse) {
-			subdir_state = read_directory_recursive(dir, path.buf,
-				path.len, check_only, simplify);
+			struct untracked_cache_dir *ud;
+			ud = lookup_untracked(dir->untracked, untracked,
+					      path.buf + baselen,
+					      path.len - baselen);
+			subdir_state =
+				read_directory_recursive(dir, path.buf, path.len,
+							 ud, check_only, simplify);
 			if (subdir_state > dir_state)
 				dir_state = subdir_state;
 		}
 
 		if (check_only) {
 			/* abort early if maximum state has been reached */
-			if (dir_state == path_untracked)
+			if (dir_state == path_untracked) {
+				if (cdir.fdir)
+					add_untracked(untracked, path.buf + baselen);
 				break;
+			}
 			/* skip the dir_add_* part */
 			continue;
 		}
@@ -1385,15 +1747,18 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 			break;
 
 		case path_untracked:
-			if (!(dir->flags & DIR_SHOW_IGNORED))
-				dir_add_name(dir, path.buf, path.len);
+			if (dir->flags & DIR_SHOW_IGNORED)
+				break;
+			dir_add_name(dir, path.buf, path.len);
+			if (cdir.fdir)
+				add_untracked(untracked, path.buf + baselen);
 			break;
 
 		default:
 			break;
 		}
 	}
-	closedir(fdir);
+	close_cached_dir(&cdir);
  out:
 	strbuf_release(&path);
 
@@ -1463,7 +1828,7 @@ static int treat_leading_path(struct dir_struct *dir,
 			break;
 		if (simplify_away(sb.buf, sb.len, simplify))
 			break;
-		if (treat_one_path(dir, &sb, simplify,
+		if (treat_one_path(dir, NULL, &sb, simplify,
 				   DT_DIR, NULL) == path_none)
 			break; /* do not recurse into it */
 		if (len <= baselen) {
@@ -1476,9 +1841,139 @@ static int treat_leading_path(struct dir_struct *dir,
 	return rc;
 }
 
+static const char *get_ident_string(void)
+{
+	static struct strbuf sb = STRBUF_INIT;
+	struct utsname uts;
+
+	if (sb.len)
+		return sb.buf;
+	if (uname(&uts))
+		die_errno(_("failed to get kernel name and information"));
+	strbuf_addf(&sb, "Location %s, system %s %s %s", get_git_work_tree(),
+		    uts.sysname, uts.release, uts.version);
+	return sb.buf;
+}
+
+static int ident_in_untracked(const struct untracked_cache *uc)
+{
+	const char *end = uc->ident.buf + uc->ident.len;
+	const char *p   = uc->ident.buf;
+
+	for (p = uc->ident.buf; p < end; p += strlen(p) + 1)
+		if (!strcmp(p, get_ident_string()))
+			return 1;
+	return 0;
+}
+
+void add_untracked_ident(struct untracked_cache *uc)
+{
+	if (ident_in_untracked(uc))
+		return;
+	strbuf_addstr(&uc->ident, get_ident_string());
+	/* this strbuf contains a list of strings, save NUL too */
+	strbuf_addch(&uc->ident, 0);
+}
+
+static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *dir,
+						      int base_len,
+						      const struct pathspec *pathspec)
+{
+	struct untracked_cache_dir *root;
+	int i;
+
+	if (!dir->untracked || getenv("GIT_DISABLE_UNTRACKED_CACHE"))
+		return NULL;
+
+	/*
+	 * We only support $GIT_DIR/info/exclude and core.excludesfile
+	 * as the global ignore rule files. Any other additions
+	 * (e.g. from command line) invalidate the cache. This
+	 * condition also catches running setup_standard_excludes()
+	 * before setting dir->untracked!
+	 */
+	if (dir->unmanaged_exclude_files)
+		return NULL;
+
+	/*
+	 * Optimize for the main use case only: whole-tree git
+	 * status. More work involved in treat_leading_path() if we
+	 * use cache on just a subset of the worktree. pathspec
+	 * support could make the matter even worse.
+	 */
+	if (base_len || (pathspec && pathspec->nr))
+		return NULL;
+
+	/* Different set of flags may produce different results */
+	if (dir->flags != dir->untracked->dir_flags ||
+	    /*
+	     * See treat_directory(), case index_nonexistent. Without
+	     * this flag, we may need to also cache .git file content
+	     * for the resolve_gitlink_ref() call, which we don't.
+	     */
+	    !(dir->flags & DIR_SHOW_OTHER_DIRECTORIES) ||
+	    /* We don't support collecting ignore files */
+	    (dir->flags & (DIR_SHOW_IGNORED | DIR_SHOW_IGNORED_TOO |
+			   DIR_COLLECT_IGNORED)))
+		return NULL;
+
+	/*
+	 * If we use .gitignore in the cache and now you change it to
+	 * .gitexclude, everything will go wrong.
+	 */
+	if (dir->exclude_per_dir != dir->untracked->exclude_per_dir &&
+	    strcmp(dir->exclude_per_dir, dir->untracked->exclude_per_dir))
+		return NULL;
+
+	/*
+	 * EXC_CMDL is not considered in the cache. If people set it,
+	 * skip the cache.
+	 */
+	if (dir->exclude_list_group[EXC_CMDL].nr)
+		return NULL;
+
+	/*
+	 * An optimization in prep_exclude() does not play well with
+	 * CE_SKIP_WORKTREE. It's a rare case anyway, if a single
+	 * entry has that bit set, disable the whole untracked cache.
+	 */
+	for (i = 0; i < active_nr; i++)
+		if (ce_skip_worktree(active_cache[i]))
+			return NULL;
+
+	if (!ident_in_untracked(dir->untracked)) {
+		warning(_("Untracked cache is disabled on this system."));
+		return NULL;
+	}
+
+	if (!dir->untracked->root) {
+		const int len = sizeof(*dir->untracked->root);
+		dir->untracked->root = xmalloc(len);
+		memset(dir->untracked->root, 0, len);
+	}
+
+	/* Validate $GIT_DIR/info/exclude and core.excludesfile */
+	root = dir->untracked->root;
+	if (hashcmp(dir->ss_info_exclude.sha1,
+		    dir->untracked->ss_info_exclude.sha1)) {
+		invalidate_gitignore(dir->untracked, root);
+		dir->untracked->ss_info_exclude = dir->ss_info_exclude;
+	}
+	if (hashcmp(dir->ss_excludes_file.sha1,
+		    dir->untracked->ss_excludes_file.sha1)) {
+		invalidate_gitignore(dir->untracked, root);
+		dir->untracked->ss_excludes_file = dir->ss_excludes_file;
+	}
+
+	/* Make sure this directory is not dropped out at saving phase */
+	root->recurse = 1;
+	return root;
+}
+
 int read_directory(struct dir_struct *dir, const char *path, int len, const struct pathspec *pathspec)
 {
 	struct path_simplify *simplify;
+	struct untracked_cache_dir *untracked;
 
 	/*
 	 * Check out create_simplify()
@@ -1502,11 +1997,39 @@ int read_directory(struct dir_struct *dir, const char *path, int len, const stru
 	 * create_simplify().
 	 */
 	simplify = create_simplify(pathspec ? pathspec->_raw : NULL);
+	untracked = validate_untracked_cache(dir, len, pathspec);
+	if (!untracked)
+		/*
+		 * make sure untracked cache code path is disabled,
+		 * e.g. prep_exclude()
+		 */
+		dir->untracked = NULL;
 	if (!len || treat_leading_path(dir, path, len, simplify))
-		read_directory_recursive(dir, path, len, 0, simplify);
+		read_directory_recursive(dir, path, len, untracked, 0, simplify);
 	free_simplify(simplify);
 	qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
 	qsort(dir->ignored, dir->ignored_nr, sizeof(struct dir_entry *), cmp_name);
+	if (dir->untracked) {
+		static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
+		trace_printf_key(&trace_untracked_stats,
+				 "node creation: %u\n"
+				 "gitignore invalidation: %u\n"
+				 "directory invalidation: %u\n"
+				 "opendir: %u\n",
+				 dir->untracked->dir_created,
+				 dir->untracked->gitignore_invalidated,
+				 dir->untracked->dir_invalidated,
+				 dir->untracked->dir_opened);
+		if (dir->untracked == the_index.untracked &&
+		    (dir->untracked->dir_opened ||
+		     dir->untracked->gitignore_invalidated ||
+		     dir->untracked->dir_invalidated))
+			the_index.cache_changed |= UNTRACKED_CHANGED;
+		if (dir->untracked != the_index.untracked) {
+			free(dir->untracked);
+			dir->untracked = NULL;
+		}
+	}
 	return dir->nr;
 }
 
@@ -1665,18 +2188,21 @@ int remove_dir_recursively(struct strbuf *path, int flag)
 void setup_standard_excludes(struct dir_struct *dir)
 {
 	const char *path;
-	char *xdg_path;
 
 	dir->exclude_per_dir = ".gitignore";
+
+	/* core.excludefile defaulting to $XDG_HOME/git/ignore */
+	if (!excludes_file)
+		excludes_file = xdg_config_home("ignore");
+	if (excludes_file && !access_or_warn(excludes_file, R_OK, 0))
+		add_excludes_from_file_1(dir, excludes_file,
+					 dir->untracked ? &dir->ss_excludes_file : NULL);
+
+	/* per repository user preference */
 	path = git_path("info/exclude");
-	if (!excludes_file) {
-		home_config_paths(NULL, &xdg_path, "ignore");
-		excludes_file = xdg_path;
-	}
 	if (!access_or_warn(path, R_OK, 0))
-		add_excludes_from_file(dir, path);
-	if (excludes_file && !access_or_warn(excludes_file, R_OK, 0))
-		add_excludes_from_file(dir, excludes_file);
+		add_excludes_from_file_1(dir, path,
+					 dir->untracked ? &dir->ss_info_exclude : NULL);
 }
 
 int remove_path(const char *name)
@@ -1728,3 +2254,404 @@ void clear_directory(struct dir_struct *dir)
 	}
 	strbuf_release(&dir->basebuf);
 }
+
+struct ondisk_untracked_cache {
+	struct stat_data info_exclude_stat;
+	struct stat_data excludes_file_stat;
+	uint32_t dir_flags;
+	unsigned char info_exclude_sha1[20];
+	unsigned char excludes_file_sha1[20];
+	char exclude_per_dir[FLEX_ARRAY];
+};
+
+#define ouc_size(len) (offsetof(struct ondisk_untracked_cache, exclude_per_dir) + len + 1)
+
+struct write_data {
+	int index;	   /* number of written untracked_cache_dir */
+	struct ewah_bitmap *check_only; /* from untracked_cache_dir */
+	struct ewah_bitmap *valid;	/* from untracked_cache_dir */
+	struct ewah_bitmap *sha1_valid; /* set if exclude_sha1 is not null */
+	struct strbuf out;
+	struct strbuf sb_stat;
+	struct strbuf sb_sha1;
+};
+
+static void stat_data_to_disk(struct stat_data *to, const struct stat_data *from)
+{
+	to->sd_ctime.sec  = htonl(from->sd_ctime.sec);
+	to->sd_ctime.nsec = htonl(from->sd_ctime.nsec);
+	to->sd_mtime.sec  = htonl(from->sd_mtime.sec);
+	to->sd_mtime.nsec = htonl(from->sd_mtime.nsec);
+	to->sd_dev	  = htonl(from->sd_dev);
+	to->sd_ino	  = htonl(from->sd_ino);
+	to->sd_uid	  = htonl(from->sd_uid);
+	to->sd_gid	  = htonl(from->sd_gid);
+	to->sd_size	  = htonl(from->sd_size);
+}
+
+static void write_one_dir(struct untracked_cache_dir *untracked,
+			  struct write_data *wd)
+{
+	struct stat_data stat_data;
+	struct strbuf *out = &wd->out;
+	unsigned char intbuf[16];
+	unsigned int intlen, value;
+	int i = wd->index++;
+
+	/*
+	 * untracked_nr should be reset whenever valid is clear, but
+	 * for safety..
+	 */
+	if (!untracked->valid) {
+		untracked->untracked_nr = 0;
+		untracked->check_only = 0;
+	}
+
+	if (untracked->check_only)
+		ewah_set(wd->check_only, i);
+	if (untracked->valid) {
+		ewah_set(wd->valid, i);
+		stat_data_to_disk(&stat_data, &untracked->stat_data);
+		strbuf_add(&wd->sb_stat, &stat_data, sizeof(stat_data));
+	}
+	if (!is_null_sha1(untracked->exclude_sha1)) {
+		ewah_set(wd->sha1_valid, i);
+		strbuf_add(&wd->sb_sha1, untracked->exclude_sha1, 20);
+	}
+
+	intlen = encode_varint(untracked->untracked_nr, intbuf);
+	strbuf_add(out, intbuf, intlen);
+
+	/* skip non-recurse directories */
+	for (i = 0, value = 0; i < untracked->dirs_nr; i++)
+		if (untracked->dirs[i]->recurse)
+			value++;
+	intlen = encode_varint(value, intbuf);
+	strbuf_add(out, intbuf, intlen);
+
+	strbuf_add(out, untracked->name, strlen(untracked->name) + 1);
+
+	for (i = 0; i < untracked->untracked_nr; i++)
+		strbuf_add(out, untracked->untracked[i],
+			   strlen(untracked->untracked[i]) + 1);
+
+	for (i = 0; i < untracked->dirs_nr; i++)
+		if (untracked->dirs[i]->recurse)
+			write_one_dir(untracked->dirs[i], wd);
+}
+
+void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked)
+{
+	struct ondisk_untracked_cache *ouc;
+	struct write_data wd;
+	unsigned char varbuf[16];
+	int len = 0, varint_len;
+	if (untracked->exclude_per_dir)
+		len = strlen(untracked->exclude_per_dir);
+	ouc = xmalloc(sizeof(*ouc) + len + 1);
+	stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
+	stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
+	hashcpy(ouc->info_exclude_sha1, untracked->ss_info_exclude.sha1);
+	hashcpy(ouc->excludes_file_sha1, untracked->ss_excludes_file.sha1);
+	ouc->dir_flags = htonl(untracked->dir_flags);
+	memcpy(ouc->exclude_per_dir, untracked->exclude_per_dir, len + 1);
+
+	varint_len = encode_varint(untracked->ident.len, varbuf);
+	strbuf_add(out, varbuf, varint_len);
+	strbuf_add(out, untracked->ident.buf, untracked->ident.len);
+
+	strbuf_add(out, ouc, ouc_size(len));
+	free(ouc);
+	ouc = NULL;
+
+	if (!untracked->root) {
+		varint_len = encode_varint(0, varbuf);
+		strbuf_add(out, varbuf, varint_len);
+		return;
+	}
+
+	wd.index      = 0;
+	wd.check_only = ewah_new();
+	wd.valid      = ewah_new();
+	wd.sha1_valid = ewah_new();
+	strbuf_init(&wd.out, 1024);
+	strbuf_init(&wd.sb_stat, 1024);
+	strbuf_init(&wd.sb_sha1, 1024);
+	write_one_dir(untracked->root, &wd);
+
+	varint_len = encode_varint(wd.index, varbuf);
+	strbuf_add(out, varbuf, varint_len);
+	strbuf_addbuf(out, &wd.out);
+	ewah_serialize_strbuf(wd.valid, out);
+	ewah_serialize_strbuf(wd.check_only, out);
+	ewah_serialize_strbuf(wd.sha1_valid, out);
+	strbuf_addbuf(out, &wd.sb_stat);
+	strbuf_addbuf(out, &wd.sb_sha1);
+	strbuf_addch(out, '\0'); /* safe guard for string lists */
+
+	ewah_free(wd.valid);
+	ewah_free(wd.check_only);
+	ewah_free(wd.sha1_valid);
+	strbuf_release(&wd.out);
+	strbuf_release(&wd.sb_stat);
+	strbuf_release(&wd.sb_sha1);
+}
+
+static void free_untracked(struct untracked_cache_dir *ucd)
+{
+	int i;
+	if (!ucd)
+		return;
+	for (i = 0; i < ucd->dirs_nr; i++)
+		free_untracked(ucd->dirs[i]);
+	for (i = 0; i < ucd->untracked_nr; i++)
+		free(ucd->untracked[i]);
+	free(ucd->untracked);
+	free(ucd->dirs);
+	free(ucd);
+}
+
+void free_untracked_cache(struct untracked_cache *uc)
+{
+	if (uc)
+		free_untracked(uc->root);
+	free(uc);
+}
+
+struct read_data {
+	int index;
+	struct untracked_cache_dir **ucd;
+	struct ewah_bitmap *check_only;
+	struct ewah_bitmap *valid;
+	struct ewah_bitmap *sha1_valid;
+	const unsigned char *data;
+	const unsigned char *end;
+};
+
+static void stat_data_from_disk(struct stat_data *to, const struct stat_data *from)
+{
+	to->sd_ctime.sec  = get_be32(&from->sd_ctime.sec);
+	to->sd_ctime.nsec = get_be32(&from->sd_ctime.nsec);
+	to->sd_mtime.sec  = get_be32(&from->sd_mtime.sec);
+	to->sd_mtime.nsec = get_be32(&from->sd_mtime.nsec);
+	to->sd_dev	  = get_be32(&from->sd_dev);
+	to->sd_ino	  = get_be32(&from->sd_ino);
+	to->sd_uid	  = get_be32(&from->sd_uid);
+	to->sd_gid	  = get_be32(&from->sd_gid);
+	to->sd_size	  = get_be32(&from->sd_size);
+}
+
+static int read_one_dir(struct untracked_cache_dir **untracked_,
+			struct read_data *rd)
+{
+	struct untracked_cache_dir ud, *untracked;
+	const unsigned char *next, *data = rd->data, *end = rd->end;
+	unsigned int value;
+	int i, len;
+
+	memset(&ud, 0, sizeof(ud));
+
+	next = data;
+	value = decode_varint(&next);
+	if (next > end)
+		return -1;
+	ud.recurse	   = 1;
+	ud.untracked_alloc = value;
+	ud.untracked_nr	   = value;
+	if (ud.untracked_nr)
+		ud.untracked = xmalloc(sizeof(*ud.untracked) * ud.untracked_nr);
+	data = next;
+
+	next = data;
+	ud.dirs_alloc = ud.dirs_nr = decode_varint(&next);
+	if (next > end)
+		return -1;
+	ud.dirs = xmalloc(sizeof(*ud.dirs) * ud.dirs_nr);
+	data = next;
+
+	len = strlen((const char *)data);
+	next = data + len + 1;
+	if (next > rd->end)
+		return -1;
+	*untracked_ = untracked = xmalloc(sizeof(*untracked) + len);
+	memcpy(untracked, &ud, sizeof(ud));
+	memcpy(untracked->name, data, len + 1);
+	data = next;
+
+	for (i = 0; i < untracked->untracked_nr; i++) {
+		len = strlen((const char *)data);
+		next = data + len + 1;
+		if (next > rd->end)
+			return -1;
+		untracked->untracked[i] = xstrdup((const char*)data);
+		data = next;
+	}
+
+	rd->ucd[rd->index++] = untracked;
+	rd->data = data;
+
+	for (i = 0; i < untracked->dirs_nr; i++) {
+		len = read_one_dir(untracked->dirs + i, rd);
+		if (len < 0)
+			return -1;
+	}
+	return 0;
+}
+
+static void set_check_only(size_t pos, void *cb)
+{
+	struct read_data *rd = cb;
+	struct untracked_cache_dir *ud = rd->ucd[pos];
+	ud->check_only = 1;
+}
+
+static void read_stat(size_t pos, void *cb)
+{
+	struct read_data *rd = cb;
+	struct untracked_cache_dir *ud = rd->ucd[pos];
+	if (rd->data + sizeof(struct stat_data) > rd->end) {
+		rd->data = rd->end + 1;
+		return;
+	}
+	stat_data_from_disk(&ud->stat_data, (struct stat_data *)rd->data);
+	rd->data += sizeof(struct stat_data);
+	ud->valid = 1;
+}
+
+static void read_sha1(size_t pos, void *cb)
+{
+	struct read_data *rd = cb;
+	struct untracked_cache_dir *ud = rd->ucd[pos];
+	if (rd->data + 20 > rd->end) {
+		rd->data = rd->end + 1;
+		return;
+	}
+	hashcpy(ud->exclude_sha1, rd->data);
+	rd->data += 20;
+}
+
+static void load_sha1_stat(struct sha1_stat *sha1_stat,
+			   const struct stat_data *stat,
+			   const unsigned char *sha1)
+{
+	stat_data_from_disk(&sha1_stat->stat, stat);
+	hashcpy(sha1_stat->sha1, sha1);
+	sha1_stat->valid = 1;
+}
+
+struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz)
+{
+	const struct ondisk_untracked_cache *ouc;
+	struct untracked_cache *uc;
+	struct read_data rd;
+	const unsigned char *next = data, *end = (const unsigned char *)data + sz;
+	const char *ident;
+	int ident_len, len;
+
+	if (sz <= 1 || end[-1] != '\0')
+		return NULL;
+	end--;
+
+	ident_len = decode_varint(&next);
+	if (next + ident_len > end)
+		return NULL;
+	ident = (const char *)next;
+	next += ident_len;
+
+	ouc = (const struct ondisk_untracked_cache *)next;
+	if (next + ouc_size(0) > end)
+		return NULL;
+
+	uc = xcalloc(1, sizeof(*uc));
+	strbuf_init(&uc->ident, ident_len);
+	strbuf_add(&uc->ident, ident, ident_len);
+	load_sha1_stat(&uc->ss_info_exclude, &ouc->info_exclude_stat,
+		       ouc->info_exclude_sha1);
+	load_sha1_stat(&uc->ss_excludes_file, &ouc->excludes_file_stat,
+		       ouc->excludes_file_sha1);
+	uc->dir_flags = get_be32(&ouc->dir_flags);
+	uc->exclude_per_dir = xstrdup(ouc->exclude_per_dir);
+	/* NUL after exclude_per_dir is covered by sizeof(*ouc) */
+	next += ouc_size(strlen(ouc->exclude_per_dir));
+	if (next >= end)
+		goto done2;
+
+	len = decode_varint(&next);
+	if (next > end || len == 0)
+		goto done2;
+
+	rd.valid      = ewah_new();
+	rd.check_only = ewah_new();
+	rd.sha1_valid = ewah_new();
+	rd.data	      = next;
+	rd.end	      = end;
+	rd.index      = 0;
+	rd.ucd        = xmalloc(sizeof(*rd.ucd) * len);
+
+	if (read_one_dir(&uc->root, &rd) || rd.index != len)
+		goto done;
+
+	next = rd.data;
+	len = ewah_read_mmap(rd.valid, next, end - next);
+	if (len < 0)
+		goto done;
+
+	next += len;
+	len = ewah_read_mmap(rd.check_only, next, end - next);
+	if (len < 0)
+		goto done;
+
+	next += len;
+	len = ewah_read_mmap(rd.sha1_valid, next, end - next);
+	if (len < 0)
+		goto done;
+
+	ewah_each_bit(rd.check_only, set_check_only, &rd);
+	rd.data = next + len;
+	ewah_each_bit(rd.valid, read_stat, &rd);
+	ewah_each_bit(rd.sha1_valid, read_sha1, &rd);
+	next = rd.data;
+
+done:
+	free(rd.ucd);
+	ewah_free(rd.valid);
+	ewah_free(rd.check_only);
+	ewah_free(rd.sha1_valid);
+done2:
+	if (next != end) {
+		free_untracked_cache(uc);
+		uc = NULL;
+	}
+	return uc;
+}
+
+void untracked_cache_invalidate_path(struct index_state *istate,
+				     const char *path)
+{
+	const char *sep;
+	struct untracked_cache_dir *d;
+	if (!istate->untracked || !istate->untracked->root)
+		return;
+	sep = strrchr(path, '/');
+	if (sep)
+		d = lookup_untracked(istate->untracked,
+				     istate->untracked->root,
+				     path, sep - path);
+	else
+		d = istate->untracked->root;
+	istate->untracked->dir_invalidated++;
+	d->valid = 0;
+	d->untracked_nr = 0;
+}
+
+void untracked_cache_remove_from_index(struct index_state *istate,
+				       const char *path)
+{
+	untracked_cache_invalidate_path(istate, path);
+}
+
+void untracked_cache_add_to_index(struct index_state *istate,
+				  const char *path)
+{
+	untracked_cache_invalidate_path(istate, path);
+}
diff --git a/dir.h b/dir.h
index 72b73c65dc..7b5855dd80 100644
--- a/dir.h
+++ b/dir.h
@@ -66,6 +66,7 @@ struct exclude_stack {
 	struct exclude_stack *prev; /* the struct exclude_stack for the parent directory */
 	int baselen;
 	int exclude_ix; /* index of exclude_list within EXC_DIRS exclude_list_group */
+	struct untracked_cache_dir *ucd;
 };
 
 struct exclude_list_group {
@@ -73,6 +74,73 @@ struct exclude_list_group {
 	struct exclude_list *el;
 };
 
+struct sha1_stat {
+	struct stat_data stat;
+	unsigned char sha1[20];
+	int valid;
+};
+
+/*
+ *  Untracked cache
+ *
+ *  The following inputs are sufficient to determine what files in a
+ *  directory are excluded:
+ *
+ *   - The list of files and directories of the directory in question
+ *   - The $GIT_DIR/index
+ *   - dir_struct flags
+ *   - The content of $GIT_DIR/info/exclude
+ *   - The content of core.excludesfile
+ *   - The content (or the lack) of .gitignore of all parent directories
+ *     from $GIT_WORK_TREE
+ *   - The check_only flag in read_directory_recursive (for
+ *     DIR_HIDE_EMPTY_DIRECTORIES)
+ *
+ *  The first input can be checked using directory mtime. In many
+ *  filesystems, directory mtime (stat_data field) is updated when its
+ *  files or direct subdirs are added or removed.
+ *
+ *  The second one can be hooked from cache_tree_invalidate_path().
+ *  Whenever a file (or a submodule) is added or removed from a
+ *  directory, we invalidate that directory.
+ *
+ *  The remaining inputs are easy, their SHA-1 could be used to verify
+ *  their contents (exclude_sha1[], info_exclude_sha1[] and
+ *  excludes_file_sha1[])
+ */
+struct untracked_cache_dir {
+	struct untracked_cache_dir **dirs;
+	char **untracked;
+	struct stat_data stat_data;
+	unsigned int untracked_alloc, dirs_nr, dirs_alloc;
+	unsigned int untracked_nr;
+	unsigned int check_only : 1;
+	/* all data except 'dirs' in this struct are good */
+	unsigned int valid : 1;
+	unsigned int recurse : 1;
+	/* null SHA-1 means this directory does not have .gitignore */
+	unsigned char exclude_sha1[20];
+	char name[FLEX_ARRAY];
+};
+
+struct untracked_cache {
+	struct sha1_stat ss_info_exclude;
+	struct sha1_stat ss_excludes_file;
+	const char *exclude_per_dir;
+	struct strbuf ident;
+	/*
+	 * dir_struct#flags must match dir_flags or the untracked
+	 * cache is ignored.
+	 */
+	unsigned dir_flags;
+	struct untracked_cache_dir *root;
+	/* Statistics */
+	int dir_created;
+	int gitignore_invalidated;
+	int dir_invalidated;
+	int dir_opened;
+};
+
 struct dir_struct {
 	int nr, alloc;
 	int ignored_nr, ignored_alloc;
@@ -120,6 +188,12 @@ struct dir_struct {
 	struct exclude_stack *exclude_stack;
 	struct exclude *exclude;
 	struct strbuf basebuf;
+
+	/* Enable untracked file cache if set */
+	struct untracked_cache *untracked;
+	struct sha1_stat ss_info_exclude;
+	struct sha1_stat ss_excludes_file;
+	unsigned unmanaged_exclude_files;
 };
 
 /*
@@ -226,4 +300,12 @@ static inline int dir_path_match(const struct dir_entry *ent,
 			      has_trailing_dir);
 }
 
+void untracked_cache_invalidate_path(struct index_state *, const char *);
+void untracked_cache_remove_from_index(struct index_state *, const char *);
+void untracked_cache_add_to_index(struct index_state *, const char *);
+
+void free_untracked_cache(struct untracked_cache *);
+struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz);
+void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
+void add_untracked_ident(struct untracked_cache *);
 #endif
diff --git a/environment.c b/environment.c
index a40044c3bf..61c685b8d9 100644
--- a/environment.c
+++ b/environment.c
@@ -92,8 +92,9 @@ static char *work_tree;
 static const char *namespace;
 static size_t namespace_len;
 
-static const char *git_dir;
+static const char *git_dir, *git_common_dir;
 static char *git_object_dir, *git_index_file, *git_graft_file;
+int git_db_env, git_index_env, git_graft_env, git_common_dir_env;
 
 /*
  * Repository-local GIT_* environment variables; see cache.h for details.
@@ -111,6 +112,7 @@ const char * const local_repo_env[] = {
 	NO_REPLACE_OBJECTS_ENVIRONMENT,
 	GIT_PREFIX_ENVIRONMENT,
 	GIT_SHALLOW_FILE_ENVIRONMENT,
+	GIT_COMMON_DIR_ENVIRONMENT,
 	NULL
 };
 
@@ -135,14 +137,23 @@ static char *expand_namespace(const char *raw_namespace)
 	return strbuf_detach(&buf, NULL);
 }
 
-static char *git_path_from_env(const char *envvar, const char *path)
+static char *git_path_from_env(const char *envvar, const char *git_dir,
+			       const char *path, int *fromenv)
 {
 	const char *value = getenv(envvar);
-	return value ? xstrdup(value) : git_pathdup("%s", path);
+	if (!value) {
+		char *buf = xmalloc(strlen(git_dir) + strlen(path) + 2);
+		sprintf(buf, "%s/%s", git_dir, path);
+		return buf;
+	}
+	if (fromenv)
+		*fromenv = 1;
+	return xstrdup(value);
 }
 
 static void setup_git_env(void)
 {
+	struct strbuf sb = STRBUF_INIT;
 	const char *gitfile;
 	const char *shallow_file;
 
@@ -151,9 +162,15 @@ static void setup_git_env(void)
 		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 	gitfile = read_gitfile(git_dir);
 	git_dir = xstrdup(gitfile ? gitfile : git_dir);
-	git_object_dir = git_path_from_env(DB_ENVIRONMENT, "objects");
-	git_index_file = git_path_from_env(INDEX_ENVIRONMENT, "index");
-	git_graft_file = git_path_from_env(GRAFT_ENVIRONMENT, "info/grafts");
+	if (get_common_dir(&sb, git_dir))
+		git_common_dir_env = 1;
+	git_common_dir = strbuf_detach(&sb, NULL);
+	git_object_dir = git_path_from_env(DB_ENVIRONMENT, git_common_dir,
+					   "objects", &git_db_env);
+	git_index_file = git_path_from_env(INDEX_ENVIRONMENT, git_dir,
+					   "index", &git_index_env);
+	git_graft_file = git_path_from_env(GRAFT_ENVIRONMENT, git_common_dir,
+					   "info/grafts", &git_graft_env);
 	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
 		check_replace_refs = 0;
 	namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
@@ -176,6 +193,11 @@ const char *get_git_dir(void)
 	return git_dir;
 }
 
+const char *get_git_common_dir(void)
+{
+	return git_common_dir;
+}
+
 const char *get_git_namespace(void)
 {
 	if (!namespace)
diff --git a/ewah/ewah_io.c b/ewah/ewah_io.c
index 1c2d7afd4c..43481b9c60 100644
--- a/ewah/ewah_io.c
+++ b/ewah/ewah_io.c
@@ -19,6 +19,7 @@
  */
 #include "git-compat-util.h"
 #include "ewok.h"
+#include "strbuf.h"
 
 int ewah_serialize_native(struct ewah_bitmap *self, int fd)
 {
@@ -110,6 +111,18 @@ int ewah_serialize(struct ewah_bitmap *self, int fd)
 	return ewah_serialize_to(self, write_helper, (void *)(intptr_t)fd);
 }
 
+static int write_strbuf(void *user_data, const void *data, size_t len)
+{
+	struct strbuf *sb = user_data;
+	strbuf_add(sb, data, len);
+	return len;
+}
+
+int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *sb)
+{
+	return ewah_serialize_to(self, write_strbuf, sb);
+}
+
 int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len)
 {
 	const uint8_t *ptr = map;
diff --git a/ewah/ewok.h b/ewah/ewok.h
index 13c6e20412..e732525367 100644
--- a/ewah/ewok.h
+++ b/ewah/ewok.h
@@ -30,6 +30,7 @@
 #	define ewah_calloc xcalloc
 #endif
 
+struct strbuf;
 typedef uint64_t eword_t;
 #define BITS_IN_WORD (sizeof(eword_t) * 8)
 
@@ -98,6 +99,7 @@ int ewah_serialize_to(struct ewah_bitmap *self,
 		      void *out);
 int ewah_serialize(struct ewah_bitmap *self, int fd);
 int ewah_serialize_native(struct ewah_bitmap *self, int fd);
+int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *);
 
 int ewah_deserialize(struct ewah_bitmap *self, int fd);
 int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len);
diff --git a/exec_cmd.c b/exec_cmd.c
index 8ab37b5f74..e85f0fd8d8 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -96,7 +96,6 @@ void setup_path(void)
 	struct strbuf new_path = STRBUF_INIT;
 
 	add_path(&new_path, git_exec_path());
-	add_path(&new_path, argv0_path);
 
 	if (old_path)
 		strbuf_addstr(&new_path, old_path);
diff --git a/fast-import.c b/fast-import.c
index e78ca107b3..6378726993 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -405,7 +405,7 @@ static void dump_marks_helper(FILE *, uintmax_t, struct mark_set *);
 
 static void write_crash_report(const char *err)
 {
-	char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
+	const char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
 	FILE *rpt = fopen(loc, "w");
 	struct branch *b;
 	unsigned long lu;
@@ -3113,12 +3113,9 @@ static void parse_progress(void)
 
 static char* make_fast_import_path(const char *path)
 {
-	struct strbuf abs_path = STRBUF_INIT;
-
 	if (!relative_marks_paths || is_absolute_path(path))
 		return xstrdup(path);
-	strbuf_addf(&abs_path, "%s/info/fast-import/%s", get_git_dir(), path);
-	return strbuf_detach(&abs_path, NULL);
+	return xstrdup(git_path("info/fast-import/%s", path));
 }
 
 static void option_import_marks(const char *marks,
diff --git a/generate-cmdlist.perl b/generate-cmdlist.perl
new file mode 100755
index 0000000000..31516e36ac
--- /dev/null
+++ b/generate-cmdlist.perl
@@ -0,0 +1,50 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+print <<"EOT";
+/* Automatically generated by $0 */
+
+struct cmdname_help {
+	char name[16];
+	char help[80];
+	unsigned char group;
+};
+
+static char *common_cmd_groups[] = {
+EOT
+
+my $n = 0;
+my %grp;
+while (<>) {
+	last if /^### command list/;
+	next if (1../^### common groups/) || /^#/ || /^\s*$/;
+	chop;
+	my ($k, $v) = split ' ', $_, 2;
+	$grp{$k} = $n++;
+	print "\tN_(\"$v\"),\n";
+}
+
+print "};\n\nstatic struct cmdname_help common_cmds[] = {\n";
+
+while (<>) {
+	next if /^#/ || /^\s*$/;
+	my @tags = split;
+	my $cmd = shift @tags;
+	for my $t (@tags) {
+		if (exists $grp{$t}) {
+			my $s;
+			open my $f, '<', "Documentation/$cmd.txt" or die;
+			while (<$f>) {
+				($s) = /^$cmd - (.+)$/;
+				last if $s;
+			}
+			close $f;
+			$cmd =~ s/^git-//;
+			print "\t{\"$cmd\", N_(\"$s\"), $grp{$t}},\n";
+			last;
+		}
+	}
+}
+
+print "};\n";
diff --git a/generate-cmdlist.sh b/generate-cmdlist.sh
deleted file mode 100755
index 9a4c9b94e6..0000000000
--- a/generate-cmdlist.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/sh
-
-echo "/* Automatically generated by $0 */
-struct cmdname_help {
-    char name[16];
-    char help[80];
-};
-
-static struct cmdname_help common_cmds[] = {"
-
-sed -n -e 's/^git-\([^ 	]*\)[ 	].* common.*/\1/p' command-list.txt |
-sort |
-while read cmd
-do
-     sed -n '
-     /^NAME/,/git-'"$cmd"'/H
-     ${
-	    x
-	    s/.*git-'"$cmd"' - \(.*\)/  {"'"$cmd"'", N_("\1")},/
-	    p
-     }' "Documentation/git-$cmd.txt"
-done
-echo "};"
diff --git a/git-am.sh b/git-am.sh
index a67d0f9898..761befbd37 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -827,10 +827,10 @@ To restore the original branch and stop patching run \"\$cmdline --abort\"."
 		continue
 	fi
 
-	if test -x "$GIT_DIR"/hooks/applypatch-msg
+	hook="$(git rev-parse --git-path hooks/applypatch-msg)"
+	if test -x "$hook"
 	then
-		"$GIT_DIR"/hooks/applypatch-msg "$dotest/final-commit" ||
-		stop_here $this
+		"$hook" "$dotest/final-commit" || stop_here $this
 	fi
 
 	if test -f "$dotest/final-commit"
@@ -904,9 +904,10 @@ did you forget to use 'git add'?"
 		stop_here_user_resolve $this
 	fi
 
-	if test -x "$GIT_DIR"/hooks/pre-applypatch
+	hook="$(git rev-parse --git-path hooks/pre-applypatch)"
+	if test -x "$hook"
 	then
-		"$GIT_DIR"/hooks/pre-applypatch || stop_here $this
+		"$hook" || stop_here $this
 	fi
 
 	tree=$(git write-tree) &&
@@ -933,18 +934,17 @@ did you forget to use 'git add'?"
 		echo "$(cat "$dotest/original-commit") $commit" >> "$dotest/rewritten"
 	fi
 
-	if test -x "$GIT_DIR"/hooks/post-applypatch
-	then
-		"$GIT_DIR"/hooks/post-applypatch
-	fi
+	hook="$(git rev-parse --git-path hooks/post-applypatch)"
+	test -x "$hook" && "$hook"
 
 	go_next
 done
 
 if test -s "$dotest"/rewritten; then
     git notes copy --for-rewrite=rebase < "$dotest"/rewritten
-    if test -x "$GIT_DIR"/hooks/post-rewrite; then
-	"$GIT_DIR"/hooks/post-rewrite rebase < "$dotest"/rewritten
+    hook="$(git rev-parse --git-path hooks/post-rewrite)"
+    if test -x "$hook"; then
+	"$hook" rebase < "$dotest"/rewritten
     fi
 fi
 
diff --git a/git-compat-util.h b/git-compat-util.h
index bc8fc8cf85..17584adbd0 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -3,6 +3,23 @@
 
 #define _FILE_OFFSET_BITS 64
 
+
+/* Derived from Linux "Features Test Macro" header
+ * Convenience macros to test the versions of gcc (or
+ * a compatible compiler).
+ * Use them like this:
+ *  #if GIT_GNUC_PREREQ (2,8)
+ *   ... code requiring gcc 2.8 or later ...
+ *  #endif
+*/
+#if defined(__GNUC__) && defined(__GNUC_MINOR__)
+# define GIT_GNUC_PREREQ(maj, min) \
+	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+#else
+ #define GIT_GNUC_PREREQ(maj, min) 0
+#endif
+
+
 #ifndef FLEX_ARRAY
 /*
  * See if our compiler is known to support flexible array members.
@@ -25,7 +42,42 @@
 #endif
 #endif
 
-#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+
+/*
+ * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
+ * @cond: the compile-time condition which must be true.
+ *
+ * Your compile will fail if the condition isn't true, or can't be evaluated
+ * by the compiler.  This can be used in an expression: its value is "0".
+ *
+ * Example:
+ *	#define foo_to_char(foo)					\
+ *		 ((char *)(foo)						\
+ *		  + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
+ */
+#define BUILD_ASSERT_OR_ZERO(cond) \
+	(sizeof(char [1 - 2*!(cond)]) - 1)
+
+#if defined(__GNUC__) && (__GNUC__ >= 3)
+# if GIT_GNUC_PREREQ(3, 1)
+ /* &arr[0] degrades to a pointer: a different type from an array */
+# define BARF_UNLESS_AN_ARRAY(arr)						\
+	BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
+							   __typeof__(&(arr)[0])))
+# else
+#  define BARF_UNLESS_AN_ARRAY(arr) 0
+# endif
+#endif
+/*
+ * ARRAY_SIZE - get the number of elements in a visible array
+ *  <at> x: the array whose size you want.
+ *
+ * This does not work on pointers, or arrays declared as [], or
+ * function parameters.  With correct compiler support, such usage
+ * will cause a build error (see the build_assert_or_zero macro).
+ */
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
+
 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
 
 #define maximum_signed_value_of_type(a) \
@@ -137,6 +189,7 @@
 #elif defined(_MSC_VER)
 #include "compat/msvc.h"
 #else
+#include <sys/utsname.h>
 #include <sys/wait.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
@@ -883,4 +936,10 @@ struct tm *git_gmtime_r(const time_t *, struct tm *);
 # define SHELL_PATH "/bin/sh"
 #endif
 
+#ifndef _POSIX_THREAD_SAFE_FUNCTIONS
+#define flockfile(fh)
+#define funlockfile(fh)
+#define getc_unlocked(fh) getc(fh)
+#endif
+
 #endif
diff --git a/git-cvsimport.perl b/git-cvsimport.perl
index 73d367cea8..82ecb0343a 100755
--- a/git-cvsimport.perl
+++ b/git-cvsimport.perl
@@ -1162,7 +1162,7 @@ sub commit {
 		die "Fast-forward update failed: $?\n" if $?;
 	}
 	else {
-		system(qw(git merge cvsimport HEAD), "$remote/$opt_o");
+		system(qw(git merge -m cvsimport), "$remote/$opt_o");
 		die "Could not merge $opt_o into the current branch.\n" if $?;
 	}
 } else {
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index e6e99f5bb5..5b3f63d8bb 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -346,7 +346,15 @@ while read commit parents; do
 				die "parent filter failed: $filter_parent"
 	fi
 
-	sed -e '1,/^$/d' <../commit | \
+	{
+		while read -r header_line && test -n "$header_line"
+		do
+			# skip header lines...
+			:;
+		done
+		# and output the actual commit message
+		cat
+	} <../commit |
 		eval "$filter_msg" > ../message ||
 			die "msg filter failed: $filter_msg"
 	workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index fe61e89f31..14b039de65 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -2,6 +2,9 @@
 
 : ${MERGE_TOOLS_DIR=$(git --exec-path)/mergetools}
 
+IFS='
+'
+
 mode_ok () {
 	if diff_mode
 	then
diff --git a/git-mergetool.sh b/git-mergetool.sh
index d20581c15c..9f77e3a8bb 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -451,8 +451,6 @@ fi
 printf "Merging:\n"
 printf "%s\n" "$files"
 
-IFS='
-'
 rc=0
 for i in $files
 do
diff --git a/git-p4.py b/git-p4.py
index 549022e97c..41a77e6648 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -368,7 +368,7 @@ def getP4OpenedType(file):
     # Returns the perforce file type for the given file.
 
     result = p4_read_pipe(["opened", wildcard_encode(file)])
-    match = re.match(".*\((.+)\)\r?$", result)
+    match = re.match(".*\((.+)\)( \*exclusive\*)?\r?$", result)
     if match:
         return match.group(1)
     else:
@@ -502,12 +502,14 @@ def p4Cmd(cmd):
 def p4Where(depotPath):
     if not depotPath.endswith("/"):
         depotPath += "/"
-    depotPath = depotPath + "..."
-    outputList = p4CmdList(["where", depotPath])
+    depotPathLong = depotPath + "..."
+    outputList = p4CmdList(["where", depotPathLong])
     output = None
     for entry in outputList:
         if "depotFile" in entry:
-            if entry["depotFile"] == depotPath:
+            # Search for the base client side depot path, as long as it starts with the branch's P4 path.
+            # The base path always ends with "/...".
+            if entry["depotFile"].find(depotPath) == 0 and entry["depotFile"][-4:] == "/...":
                 output = entry
                 break
         elif "data" in entry:
@@ -740,17 +742,43 @@ def createOrUpdateBranchesFromOrigin(localRefPrefix = "refs/remotes/p4/", silent
 def originP4BranchesExist():
         return gitBranchExists("origin") or gitBranchExists("origin/p4") or gitBranchExists("origin/p4/master")
 
-def p4ChangesForPaths(depotPaths, changeRange):
+def p4ChangesForPaths(depotPaths, changeRange, block_size):
     assert depotPaths
-    cmd = ['changes']
-    for p in depotPaths:
-        cmd += ["%s...%s" % (p, changeRange)]
-    output = p4_read_pipe_lines(cmd)
+    assert block_size
+
+    # Parse the change range into start and end
+    if changeRange is None or changeRange == '':
+        changeStart = '@1'
+        changeEnd = '#head'
+    else:
+        parts = changeRange.split(',')
+        assert len(parts) == 2
+        changeStart = parts[0]
+        changeEnd = parts[1]
 
+    # Accumulate change numbers in a dictionary to avoid duplicates
     changes = {}
-    for line in output:
-        changeNum = int(line.split(" ")[1])
-        changes[changeNum] = True
+
+    for p in depotPaths:
+        # Retrieve changes a block at a time, to prevent running
+        # into a MaxScanRows error from the server.
+        start = changeStart
+        end = changeEnd
+        get_another_block = True
+        while get_another_block:
+            new_changes = []
+            cmd = ['changes']
+            cmd += ['-m', str(block_size)]
+            cmd += ["%s...%s,%s" % (p, start, end)]
+            for line in p4_read_pipe_lines(cmd):
+                changeNum = int(line.split(" ")[1])
+                new_changes.append(changeNum)
+                changes[changeNum] = True
+            if len(new_changes) == block_size:
+                get_another_block = True
+                end = '@' + str(min(new_changes))
+            else:
+                get_another_block = False
 
     changelist = changes.keys()
     changelist.sort()
@@ -1627,7 +1655,10 @@ def run(self, args):
         if self.useClientSpec:
             self.clientSpecDirs = getClientSpec()
 
-        if self.useClientSpec:
+        # Check for the existance of P4 branches
+        branchesDetected = (len(p4BranchesInGit().keys()) > 1)
+
+        if self.useClientSpec and not branchesDetected:
             # all files are relative to the client spec
             self.clientPath = getClientRoot()
         else:
@@ -1911,7 +1942,10 @@ def __init__(self):
                 optparse.make_option("--import-labels", dest="importLabels", action="store_true"),
                 optparse.make_option("--import-local", dest="importIntoRemotes", action="store_false",
                                      help="Import into refs/heads/ , not refs/remotes"),
-                optparse.make_option("--max-changes", dest="maxChanges"),
+                optparse.make_option("--max-changes", dest="maxChanges",
+                                     help="Maximum number of changes to import"),
+                optparse.make_option("--changes-block-size", dest="changes_block_size", type="int",
+                                     help="Internal block size to use when iteratively calling p4 changes"),
                 optparse.make_option("--keep-path", dest="keepRepoPath", action='store_true',
                                      help="Keep entire BRANCH/DIR/SUBDIR prefix during import"),
                 optparse.make_option("--use-client-spec", dest="useClientSpec", action='store_true',
@@ -1940,6 +1974,7 @@ def __init__(self):
         self.syncWithOrigin = True
         self.importIntoRemotes = True
         self.maxChanges = ""
+        self.changes_block_size = 500
         self.keepRepoPath = False
         self.depotPaths = None
         self.p4BranchesInGit = []
@@ -2586,7 +2621,7 @@ def importNewBranch(self, branch, maxChange):
         branchPrefix = self.depotPaths[0] + branch + "/"
         range = "@1,%s" % maxChange
         #print "prefix" + branchPrefix
-        changes = p4ChangesForPaths([branchPrefix], range)
+        changes = p4ChangesForPaths([branchPrefix], range, self.changes_block_size)
         if len(changes) <= 0:
             return False
         firstChange = changes[0]
@@ -3002,7 +3037,7 @@ def run(self, args):
                 if self.verbose:
                     print "Getting p4 changes for %s...%s" % (', '.join(self.depotPaths),
                                                               self.changeRange)
-                changes = p4ChangesForPaths(self.depotPaths, self.changeRange)
+                changes = p4ChangesForPaths(self.depotPaths, self.changeRange, self.changes_block_size)
 
                 if len(self.maxChanges) > 0:
                     changes = changes[:min(int(self.maxChanges), len(changes))]
diff --git a/git-pull.sh b/git-pull.sh
index 4d4fc77b05..0917d0d056 100755
--- a/git-pull.sh
+++ b/git-pull.sh
@@ -54,8 +54,11 @@ then
 fi
 
 # Setup default fast-forward options via `pull.ff`
-pull_ff=$(git config pull.ff)
+pull_ff=$(bool_or_string_config pull.ff)
 case "$pull_ff" in
+true)
+	no_ff=--ff
+	;;
 false)
 	no_ff=--no-ff
 	;;
@@ -81,8 +84,8 @@ do
 		diffstat=--no-stat ;;
 	--stat|--summary)
 		diffstat=--stat ;;
-	--log|--no-log)
-		log_arg=$1 ;;
+	--log|--log=*|--no-log)
+		log_arg="$1" ;;
 	--no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
 		no_commit=--no-commit ;;
 	--c|--co|--com|--comm|--commi|--commit)
@@ -190,15 +193,6 @@ esac
 
 error_on_no_merge_candidates () {
 	exec >&2
-	for opt
-	do
-		case "$opt" in
-		-t|--t|--ta|--tag|--tags)
-			echo "It doesn't make sense to pull all tags; you probably meant:"
-			echo "  git fetch --tags"
-			exit 1
-		esac
-	done
 
 	if test true = "$rebase"
 	then
@@ -240,7 +234,7 @@ test true = "$rebase" && {
 	if ! git rev-parse -q --verify HEAD >/dev/null
 	then
 		# On an unborn branch
-		if test -f "$GIT_DIR/index"
+		if test -f "$(git rev-parse --git-path index)"
 		then
 			die "$(gettext "updating an unborn branch with changes added to the index")"
 		fi
@@ -323,7 +317,6 @@ then
 	fi
 fi
 
-merge_name=$(git fmt-merge-msg $log_arg <"$GIT_DIR/FETCH_HEAD") || exit
 case "$rebase" in
 true)
 	eval="git-rebase $diffstat $strategy_args $merge_args $rebase_args $verbosity"
@@ -334,7 +327,7 @@ true)
 	eval="git-merge $diffstat $no_commit $verify_signatures $edit $squash $no_ff $ff_only"
 	eval="$eval $log_arg $strategy_args $merge_args $verbosity $progress"
 	eval="$eval $gpg_sign_args"
-	eval="$eval \"\$merge_name\" HEAD $merge_head"
+	eval="$eval FETCH_HEAD"
 	;;
 esac
 eval "exec $eval"
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index f7deeb096e..bab0dccc04 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -132,6 +132,16 @@ mark_action_done () {
 	fi
 }
 
+# Put the last action marked done at the beginning of the todo list
+# again. If there has not been an action marked done yet, leave the list of
+# items on the todo list unchanged.
+reschedule_last_action () {
+	tail -n 1 "$done" | cat - "$todo" >"$todo".new
+	sed -e \$d <"$done" >"$done".new
+	mv -f "$todo".new "$todo"
+	mv -f "$done".new "$done"
+}
+
 append_todo_help () {
 	git stripspace --comment-lines >>"$todo" <<\EOF
 
@@ -252,6 +262,12 @@ pick_one () {
 	output eval git cherry-pick \
 			${gpg_sign_opt:+$(git rev-parse --sq-quote "$gpg_sign_opt")} \
 			"$strategy_args" $empty_args $ff "$@"
+
+	# If cherry-pick dies it leaves the to-be-picked commit unrecorded. Reschedule
+	# previous task so this commit is not lost.
+	ret=$?
+	case "$ret" in [01]) ;; *) reschedule_last_action ;; esac
+	return $ret
 }
 
 pick_one_preserving_merges () {
@@ -642,9 +658,9 @@ do_next () {
 		git notes copy --for-rewrite=rebase < "$rewritten_list" ||
 		true # we don't care if this copying failed
 	} &&
-	if test -x "$GIT_DIR"/hooks/post-rewrite &&
-		test -s "$rewritten_list"; then
-		"$GIT_DIR"/hooks/post-rewrite rebase < "$rewritten_list"
+	hook="$(git rev-parse --git-path hooks/post-rewrite)"
+	if test -x "$hook" && test -s "$rewritten_list"; then
+		"$hook" rebase < "$rewritten_list"
 		true # we don't care if this hook failed
 	fi &&
 	warn "Successfully rebased and updated $head_name."
diff --git a/git-rebase--merge.sh b/git-rebase--merge.sh
index d3fb67d75b..2cc2a6d273 100644
--- a/git-rebase--merge.sh
+++ b/git-rebase--merge.sh
@@ -94,10 +94,8 @@ finish_rb_merge () {
 	if test -s "$state_dir"/rewritten
 	then
 		git notes copy --for-rewrite=rebase <"$state_dir"/rewritten
-		if test -x "$GIT_DIR"/hooks/post-rewrite
-		then
-			"$GIT_DIR"/hooks/post-rewrite rebase <"$state_dir"/rewritten
-		fi
+		hook="$(git rev-parse --git-path hooks/post-rewrite)"
+		test -x "$hook" && "$hook" rebase <"$state_dir"/rewritten
 	fi
 	say All done.
 }
diff --git a/git-rebase.sh b/git-rebase.sh
index 55da9db818..1757404bc2 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -202,9 +202,9 @@ run_specific_rebase () {
 
 run_pre_rebase_hook () {
 	if test -z "$ok_to_skip_pre_rebase" &&
-	   test -x "$GIT_DIR/hooks/pre-rebase"
+	   test -x "$(git rev-parse --git-path hooks/pre-rebase)"
 	then
-		"$GIT_DIR/hooks/pre-rebase" ${1+"$@"} ||
+		"$(git rev-parse --git-path hooks/pre-rebase)" ${1+"$@"} ||
 		die "$(gettext "The pre-rebase hook refused to rebase.")"
 	fi
 }
@@ -582,7 +582,7 @@ then
 		# Lazily switch to the target branch if needed...
 		test -z "$switch_to" ||
 		GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $switch_to" \
-			git checkout "$switch_to" --
+			git checkout -q "$switch_to" --
 		say "$(eval_gettext "Current branch \$branch_name is up to date.")"
 		finish_rebase
 		exit 0
diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index c42c6e6365..4691fbcb64 100644
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -344,7 +344,7 @@ git_dir_init () {
 		echo >&2 "Unable to determine absolute path of git directory"
 		exit 1
 	}
-	: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
+	: ${GIT_OBJECT_DIRECTORY="$(git rev-parse --git-path objects)"}
 }
 
 if test -z "$NONGIT_OK"
diff --git a/git-stash.sh b/git-stash.sh
index d4cf818be9..1f5ea877d7 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -20,7 +20,7 @@ require_work_tree
 cd_to_toplevel
 
 TMP="$GIT_DIR/.git-stash.$$"
-TMPindex=${GIT_INDEX_FILE-"$GIT_DIR/index"}.stash.$$
+TMPindex=${GIT_INDEX_FILE-"$(git rev-parse --git-path index)"}.stash.$$
 trap 'rm -f "$TMP-"* "$TMPindex"' 0
 
 ref_stash=refs/stash
@@ -184,7 +184,7 @@ store_stash () {
 	fi
 
 	# Make sure the reflog for stash is kept.
-	: >>"$GIT_DIR/logs/$ref_stash"
+	: >>"$(git rev-parse --git-path logs/$ref_stash)"
 	git update-ref -m "$stash_msg" $ref_stash $w_commit
 	ret=$?
 	test $ret != 0 && test -z $quiet &&
@@ -219,6 +219,9 @@ save_stash () {
 		-a|--all)
 			untracked=all
 			;;
+		--help)
+			show_help
+			;;
 		--)
 			shift
 			break
@@ -259,7 +262,7 @@ save_stash () {
 		say "$(gettext "No local changes to save")"
 		exit 0
 	fi
-	test -f "$GIT_DIR/logs/$ref_stash" ||
+	test -f "$(git rev-parse --git-path logs/$ref_stash)" ||
 		clear_stash || die "$(gettext "Cannot initialize stash")"
 
 	create_stash "$stash_msg" $untracked
@@ -301,11 +304,17 @@ list_stash () {
 }
 
 show_stash () {
+	ALLOW_UNKNOWN_FLAGS=t
 	assert_stash_like "$@"
 
 	git diff ${FLAGS:---stat} $b_commit $w_commit
 }
 
+show_help () {
+	exec git help stash
+	exit 1
+}
+
 #
 # Parses the remaining options looking for flags and
 # at most one revision defaulting to ${ref_stash}@{0}
@@ -332,13 +341,14 @@ show_stash () {
 #
 #   GIT_QUIET is set to t if -q is specified
 #   INDEX_OPTION is set to --index if --index is specified.
-#   FLAGS is set to the remaining flags
+#   FLAGS is set to the remaining flags (if allowed)
 #
 # dies if:
 #   * too many revisions specified
 #   * no revision is specified and there is no stash stack
 #   * a revision is specified which cannot be resolve to a SHA1
 #   * a non-existent stash reference is specified
+#   * unknown flags were set and ALLOW_UNKNOWN_FLAGS is not "t"
 #
 
 parse_flags_and_rev()
@@ -371,7 +381,12 @@ parse_flags_and_rev()
 			--index)
 				INDEX_OPTION=--index
 			;;
+			--help)
+				show_help
+			;;
 			-*)
+				test "$ALLOW_UNKNOWN_FLAGS" = t ||
+					die "$(eval_gettext "unknown option: \$opt")"
 				FLAGS="${FLAGS}${FLAGS:+ }$opt"
 			;;
 		esac
@@ -442,6 +457,8 @@ apply_stash () {
 	assert_stash_like "$@"
 
 	git update-index -q --refresh || die "$(gettext "unable to refresh index")"
+	git diff-index --cached --quiet --ignore-submodules HEAD -- ||
+		die "$(gettext "Cannot apply stash: Your index contains uncommitted changes.")"
 
 	# current index state
 	c_tree=$(git write-tree) ||
diff --git a/git.c b/git.c
index 42a4ee5784..44374b1d9b 100644
--- a/git.c
+++ b/git.c
@@ -382,7 +382,7 @@ static struct cmd_struct commands[] = {
 	{ "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 	{ "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 	{ "check-ref-format", cmd_check_ref_format },
-	{ "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
+	{ "checkout", cmd_checkout, RUN_SETUP },
 	{ "checkout-index", cmd_checkout_index,
 		RUN_SETUP | NEED_WORK_TREE},
 	{ "cherry", cmd_cherry, RUN_SETUP },
diff --git a/help.c b/help.c
index 2072a873e2..8f72051ae0 100644
--- a/help.c
+++ b/help.c
@@ -218,17 +218,39 @@ void list_commands(unsigned int colopts,
 	}
 }
 
+static int cmd_group_cmp(const void *elem1, const void *elem2)
+{
+	const struct cmdname_help *e1 = elem1;
+	const struct cmdname_help *e2 = elem2;
+
+	if (e1->group < e2->group)
+		return -1;
+	if (e1->group > e2->group)
+		return 1;
+	return strcmp(e1->name, e2->name);
+}
+
 void list_common_cmds_help(void)
 {
 	int i, longest = 0;
+	int current_grp = -1;
 
 	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 		if (longest < strlen(common_cmds[i].name))
 			longest = strlen(common_cmds[i].name);
 	}
 
-	puts(_("The most commonly used git commands are:"));
+	qsort(common_cmds, ARRAY_SIZE(common_cmds),
+		sizeof(common_cmds[0]), cmd_group_cmp);
+
+	puts(_("These are common Git commands used in various situations:"));
+
 	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
+		if (common_cmds[i].group != current_grp) {
+			printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
+			current_grp = common_cmds[i].group;
+		}
+
 		printf("   %s   ", common_cmds[i].name);
 		mput_char(' ', longest - strlen(common_cmds[i].name));
 		puts(_(common_cmds[i].help));
diff --git a/hex.c b/hex.c
index cfd9d722fd..899b74a08c 100644
--- a/hex.c
+++ b/hex.c
@@ -38,7 +38,7 @@ const signed char hexval_table[256] = {
 int get_sha1_hex(const char *hex, unsigned char *sha1)
 {
 	int i;
-	for (i = 0; i < 20; i++) {
+	for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
 		unsigned int val;
 		/*
 		 * hex[1]=='\0' is caught when val is checked below,
@@ -56,15 +56,20 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
+int get_oid_hex(const char *hex, struct object_id *oid)
+{
+	return get_sha1_hex(hex, oid->hash);
+}
+
 char *sha1_to_hex(const unsigned char *sha1)
 {
 	static int bufno;
-	static char hexbuffer[4][41];
+	static char hexbuffer[4][GIT_SHA1_HEXSZ + 1];
 	static const char hex[] = "0123456789abcdef";
 	char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
 	int i;
 
-	for (i = 0; i < 20; i++) {
+	for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
 		unsigned int val = *sha1++;
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
@@ -73,3 +78,8 @@ char *sha1_to_hex(const unsigned char *sha1)
 
 	return buffer;
 }
+
+char *oid_to_hex(const struct object_id *oid)
+{
+	return sha1_to_hex(oid->hash);
+}
diff --git a/http-backend.c b/http-backend.c
index b6c0484fb2..6bf139b768 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -13,18 +13,20 @@ static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
 static const char last_modified[] = "Last-Modified";
 static int getanyfile = 1;
+static unsigned long max_request_buffer = 10 * 1024 * 1024;
 
 static struct string_list *query_params;
 
 struct rpc_service {
 	const char *name;
 	const char *config_name;
+	unsigned buffer_input : 1;
 	signed enabled : 2;
 };
 
 static struct rpc_service rpc_service[] = {
-	{ "upload-pack", "uploadpack", 1 },
-	{ "receive-pack", "receivepack", -1 },
+	{ "upload-pack", "uploadpack", 1, 1 },
+	{ "receive-pack", "receivepack", 0, -1 },
 };
 
 static struct string_list *get_parameters(void)
@@ -225,6 +227,7 @@ static void http_config(void)
 	struct strbuf var = STRBUF_INIT;
 
 	git_config_get_bool("http.getanyfile", &getanyfile);
+	git_config_get_ulong("http.maxrequestbuffer", &max_request_buffer);
 
 	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 		struct rpc_service *svc = &rpc_service[i];
@@ -266,9 +269,52 @@ static struct rpc_service *select_service(const char *name)
 	return svc;
 }
 
-static void inflate_request(const char *prog_name, int out)
+/*
+ * This is basically strbuf_read(), except that if we
+ * hit max_request_buffer we die (we'd rather reject a
+ * maliciously large request than chew up infinite memory).
+ */
+static ssize_t read_request(int fd, unsigned char **out)
+{
+	size_t len = 0, alloc = 8192;
+	unsigned char *buf = xmalloc(alloc);
+
+	if (max_request_buffer < alloc)
+		max_request_buffer = alloc;
+
+	while (1) {
+		ssize_t cnt;
+
+		cnt = read_in_full(fd, buf + len, alloc - len);
+		if (cnt < 0) {
+			free(buf);
+			return -1;
+		}
+
+		/* partial read from read_in_full means we hit EOF */
+		len += cnt;
+		if (len < alloc) {
+			*out = buf;
+			return len;
+		}
+
+		/* otherwise, grow and try again (if we can) */
+		if (alloc == max_request_buffer)
+			die("request was larger than our maximum size (%lu);"
+			    " try setting GIT_HTTP_MAX_REQUEST_BUFFER",
+			    max_request_buffer);
+
+		alloc = alloc_nr(alloc);
+		if (alloc > max_request_buffer)
+			alloc = max_request_buffer;
+		REALLOC_ARRAY(buf, alloc);
+	}
+}
+
+static void inflate_request(const char *prog_name, int out, int buffer_input)
 {
 	git_zstream stream;
+	unsigned char *full_request = NULL;
 	unsigned char in_buf[8192];
 	unsigned char out_buf[8192];
 	unsigned long cnt = 0;
@@ -277,11 +323,21 @@ static void inflate_request(const char *prog_name, int out)
 	git_inflate_init_gzip_only(&stream);
 
 	while (1) {
-		ssize_t n = xread(0, in_buf, sizeof(in_buf));
+		ssize_t n;
+
+		if (buffer_input) {
+			if (full_request)
+				n = 0; /* nothing left to read */
+			else
+				n = read_request(0, &full_request);
+			stream.next_in = full_request;
+		} else {
+			n = xread(0, in_buf, sizeof(in_buf));
+			stream.next_in = in_buf;
+		}
+
 		if (n <= 0)
 			die("request ended in the middle of the gzip stream");
-
-		stream.next_in = in_buf;
 		stream.avail_in = n;
 
 		while (0 < stream.avail_in) {
@@ -307,9 +363,22 @@ static void inflate_request(const char *prog_name, int out)
 done:
 	git_inflate_end(&stream);
 	close(out);
+	free(full_request);
+}
+
+static void copy_request(const char *prog_name, int out)
+{
+	unsigned char *buf;
+	ssize_t n = read_request(0, &buf);
+	if (n < 0)
+		die_errno("error reading request body");
+	if (write_in_full(out, buf, n) != n)
+		die("%s aborted reading request", prog_name);
+	close(out);
+	free(buf);
 }
 
-static void run_service(const char **argv)
+static void run_service(const char **argv, int buffer_input)
 {
 	const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 	const char *user = getenv("REMOTE_USER");
@@ -334,7 +403,7 @@ static void run_service(const char **argv)
 				 "GIT_COMMITTER_EMAIL=%s@http.%s", user, host);
 
 	cld.argv = argv;
-	if (gzipped_request)
+	if (buffer_input || gzipped_request)
 		cld.in = -1;
 	cld.git_cmd = 1;
 	if (start_command(&cld))
@@ -342,7 +411,9 @@ static void run_service(const char **argv)
 
 	close(1);
 	if (gzipped_request)
-		inflate_request(argv[0], cld.in);
+		inflate_request(argv[0], cld.in, buffer_input);
+	else if (buffer_input)
+		copy_request(argv[0], cld.in);
 	else
 		close(0);
 
@@ -392,7 +463,7 @@ static void get_info_refs(char *arg)
 		packet_flush(1);
 
 		argv[0] = svc->name;
-		run_service(argv);
+		run_service(argv, 0);
 
 	} else {
 		select_getanyfile();
@@ -496,25 +567,28 @@ static void service_rpc(char *service_name)
 	end_headers();
 
 	argv[0] = svc->name;
-	run_service(argv);
+	run_service(argv, svc->buffer_input);
 	strbuf_release(&buf);
 }
 
+static int dead;
 static NORETURN void die_webcgi(const char *err, va_list params)
 {
-	static int dead;
+	if (dead <= 1) {
+		vreportf("fatal: ", err, params);
 
-	if (!dead) {
-		dead = 1;
 		http_status(500, "Internal Server Error");
 		hdr_nocache();
 		end_headers();
-
-		vreportf("fatal: ", err, params);
 	}
 	exit(0); /* we successfully reported a failure ;-) */
 }
 
+static int die_webcgi_recursing(void)
+{
+	return dead++ > 1;
+}
+
 static char* getdir(void)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -569,6 +643,7 @@ int main(int argc, char **argv)
 
 	git_extract_argv0_path(argv[0]);
 	set_die_routine(die_webcgi);
+	set_die_is_recursing_routine(die_webcgi_recursing);
 
 	if (!method)
 		die("No REQUEST_METHOD from server");
@@ -619,6 +694,9 @@ int main(int argc, char **argv)
 		not_found("Repository not exported: '%s'", dir);
 
 	http_config();
+	max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
+					   max_request_buffer);
+
 	cmd->imp(cmd_arg);
 	return 0;
 }
diff --git a/http.c b/http.c
index 4b179f6fc8..f0c5bbc8b5 100644
--- a/http.c
+++ b/http.c
@@ -36,6 +36,7 @@ char curl_errorstr[CURL_ERROR_SIZE];
 static int curl_ssl_verify = -1;
 static int curl_ssl_try;
 static const char *ssl_cert;
+static const char *ssl_cipherlist;
 #if LIBCURL_VERSION_NUM >= 0x070903
 static const char *ssl_key;
 #endif
@@ -187,6 +188,8 @@ static int http_options(const char *var, const char *value, void *cb)
 		curl_ssl_verify = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp("http.sslcipherlist", var))
+		return git_config_string(&ssl_cipherlist, var, value);
 	if (!strcmp("http.sslcert", var))
 		return git_config_string(&ssl_cert, var, value);
 #if LIBCURL_VERSION_NUM >= 0x070903
@@ -361,6 +364,13 @@ static CURL *get_curl_handle(void)
 	if (http_proactive_auth)
 		init_curl_http_auth(result);
 
+	if (getenv("GIT_SSL_CIPHER_LIST"))
+		ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
+
+	if (ssl_cipherlist != NULL && *ssl_cipherlist)
+		curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
+				ssl_cipherlist);
+
 	if (ssl_cert != NULL)
 		curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 	if (has_cert_password())
diff --git a/line-log.c b/line-log.c
index a490efea07..a5ed9e3642 100644
--- a/line-log.c
+++ b/line-log.c
@@ -575,7 +575,7 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 
 		name_part = skip_range_arg(item->string);
 		if (!name_part || *name_part != ':' || !name_part[1])
-			die("-L argument '%s' not of the form start,end:file",
+			die("-L argument not 'start,end:file' or ':funcname:file': %s",
 			    item->string);
 		range_part = xstrndup(item->string, name_part - item->string);
 		name_part++;
@@ -1099,6 +1099,7 @@ static int process_all_files(struct line_log_data **range_out,
 			rg->pair = diff_filepair_dup(queue->queue[i]);
 			memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
 		}
+		free(pairdiff);
 	}
 
 	return changed;
diff --git a/lockfile.c b/lockfile.c
index 9889277751..5a93bc7bc2 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -157,6 +157,80 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
 	return lk->fd;
 }
 
+static int sleep_microseconds(long us)
+{
+	struct timeval tv;
+	tv.tv_sec = 0;
+	tv.tv_usec = us;
+	return select(0, NULL, NULL, NULL, &tv);
+}
+
+/*
+ * Constants defining the gaps between attempts to lock a file. The
+ * first backoff period is approximately INITIAL_BACKOFF_MS
+ * milliseconds. The longest backoff period is approximately
+ * (BACKOFF_MAX_MULTIPLIER * INITIAL_BACKOFF_MS) milliseconds.
+ */
+#define INITIAL_BACKOFF_MS 1L
+#define BACKOFF_MAX_MULTIPLIER 1000
+
+/*
+ * Try locking path, retrying with quadratic backoff for at least
+ * timeout_ms milliseconds. If timeout_ms is 0, try locking the file
+ * exactly once. If timeout_ms is -1, try indefinitely.
+ */
+static int lock_file_timeout(struct lock_file *lk, const char *path,
+			     int flags, long timeout_ms)
+{
+	int n = 1;
+	int multiplier = 1;
+	long remaining_us = 0;
+	static int random_initialized = 0;
+
+	if (timeout_ms == 0)
+		return lock_file(lk, path, flags);
+
+	if (!random_initialized) {
+		srandom((unsigned int)getpid());
+		random_initialized = 1;
+	}
+
+	if (timeout_ms > 0) {
+		/* avoid overflow */
+		if (timeout_ms <= LONG_MAX / 1000)
+			remaining_us = timeout_ms * 1000;
+		else
+			remaining_us = LONG_MAX;
+	}
+
+	while (1) {
+		long backoff_ms, wait_us;
+		int fd;
+
+		fd = lock_file(lk, path, flags);
+
+		if (fd >= 0)
+			return fd; /* success */
+		else if (errno != EEXIST)
+			return -1; /* failure other than lock held */
+		else if (timeout_ms > 0 && remaining_us <= 0)
+			return -1; /* failure due to timeout */
+
+		backoff_ms = multiplier * INITIAL_BACKOFF_MS;
+		/* back off for between 0.75*backoff_ms and 1.25*backoff_ms */
+		wait_us = (750 + random() % 500) * backoff_ms;
+		sleep_microseconds(wait_us);
+		remaining_us -= wait_us;
+
+		/* Recursion: (n+1)^2 = n^2 + 2n + 1 */
+		multiplier += 2*n + 1;
+		if (multiplier > BACKOFF_MAX_MULTIPLIER)
+			multiplier = BACKOFF_MAX_MULTIPLIER;
+		else
+			n++;
+	}
+}
+
 void unable_to_lock_message(const char *path, int err, struct strbuf *buf)
 {
 	if (err == EEXIST) {
@@ -179,9 +253,10 @@ NORETURN void unable_to_lock_die(const char *path, int err)
 }
 
 /* This should return a meaningful errno on failure */
-int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags)
+int hold_lock_file_for_update_timeout(struct lock_file *lk, const char *path,
+				      int flags, long timeout_ms)
 {
-	int fd = lock_file(lk, path, flags);
+	int fd = lock_file_timeout(lk, path, flags, timeout_ms);
 	if (fd < 0 && (flags & LOCK_DIE_ON_ERROR))
 		unable_to_lock_die(path, errno);
 	return fd;
@@ -214,7 +289,7 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags)
 		int save_errno = errno;
 
 		if (flags & LOCK_DIE_ON_ERROR)
-			exit(128);
+			die("failed to prepare '%s' for appending", path);
 		close(orig_fd);
 		rollback_lock_file(lk);
 		errno = save_errno;
diff --git a/lockfile.h b/lockfile.h
index cd2ec95d30..b4abc61c00 100644
--- a/lockfile.h
+++ b/lockfile.h
@@ -74,8 +74,20 @@ struct lock_file {
 extern void unable_to_lock_message(const char *path, int err,
 				   struct strbuf *buf);
 extern NORETURN void unable_to_lock_die(const char *path, int err);
-extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
-extern int hold_lock_file_for_append(struct lock_file *, const char *path, int);
+extern int hold_lock_file_for_update_timeout(
+		struct lock_file *lk, const char *path,
+		int flags, long timeout_ms);
+
+static inline int hold_lock_file_for_update(
+		struct lock_file *lk, const char *path,
+		int flags)
+{
+	return hold_lock_file_for_update_timeout(lk, path, flags, 0);
+}
+
+extern int hold_lock_file_for_append(struct lock_file *lk, const char *path,
+				     int flags);
+
 extern FILE *fdopen_lock_file(struct lock_file *, const char *mode);
 extern char *get_locked_file_path(struct lock_file *);
 extern int commit_lock_file_to(struct lock_file *, const char *path);
diff --git a/log-tree.c b/log-tree.c
index 2c1ed0fa90..8dba7be92e 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -13,6 +13,8 @@
 #include "line-log.h"
 
 static struct decoration name_decoration = { "object names" };
+static int decoration_loaded;
+static int decoration_flags;
 
 static char decoration_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RESET,
@@ -92,6 +94,8 @@ static int add_ref_decoration(const char *refname, const unsigned char *sha1, in
 	struct object *obj;
 	enum decoration_type type = DECORATION_NONE;
 
+	assert(cb_data == NULL);
+
 	if (starts_with(refname, "refs/replace/")) {
 		unsigned char original_sha1[20];
 		if (!check_replace_refs)
@@ -121,8 +125,6 @@ static int add_ref_decoration(const char *refname, const unsigned char *sha1, in
 	else if (!strcmp(refname, "HEAD"))
 		type = DECORATION_REF_HEAD;
 
-	if (!cb_data || *(int *)cb_data == DECORATE_SHORT_REFS)
-		refname = prettify_refname(refname);
 	add_name_decoration(type, refname, obj);
 	while (obj->type == OBJ_TAG) {
 		obj = ((struct tag *)obj)->tagged;
@@ -137,7 +139,7 @@ static int add_ref_decoration(const char *refname, const unsigned char *sha1, in
 
 static int add_graft_decoration(const struct commit_graft *graft, void *cb_data)
 {
-	struct commit *commit = lookup_commit(graft->sha1);
+	struct commit *commit = lookup_commit(graft->oid.hash);
 	if (!commit)
 		return 0;
 	add_name_decoration(DECORATION_GRAFTED, "grafted", &commit->object);
@@ -146,11 +148,11 @@ static int add_graft_decoration(const struct commit_graft *graft, void *cb_data)
 
 void load_ref_decorations(int flags)
 {
-	static int loaded;
-	if (!loaded) {
-		loaded = 1;
-		for_each_ref(add_ref_decoration, &flags);
-		head_ref(add_ref_decoration, &flags);
+	if (!decoration_loaded) {
+		decoration_loaded = 1;
+		decoration_flags = flags;
+		for_each_ref(add_ref_decoration, NULL);
+		head_ref(add_ref_decoration, NULL);
 		for_each_commit_graft(add_graft_decoration, NULL);
 	}
 }
@@ -196,7 +198,8 @@ static const struct name_decoration *current_pointed_by_HEAD(const struct name_d
 	branch_name = resolve_ref_unsafe("HEAD", 0, unused, &rru_flags);
 	if (!(rru_flags & REF_ISSYMREF))
 		return NULL;
-	if (!skip_prefix(branch_name, "refs/heads/", &branch_name))
+
+	if (!starts_with(branch_name, "refs/"))
 		return NULL;
 
 	/* OK, do we have that ref in the list? */
@@ -209,6 +212,14 @@ static const struct name_decoration *current_pointed_by_HEAD(const struct name_d
 	return NULL;
 }
 
+static void show_name(struct strbuf *sb, const struct name_decoration *decoration)
+{
+	if (decoration_flags == DECORATE_SHORT_REFS)
+		strbuf_addstr(sb, prettify_refname(decoration->name));
+	else
+		strbuf_addstr(sb, decoration->name);
+}
+
 /*
  * The caller makes sure there is no funny color before calling.
  * format_decorations_extended makes sure the same after return.
@@ -246,7 +257,7 @@ void format_decorations_extended(struct strbuf *sb,
 			if (decoration->type == DECORATION_REF_TAG)
 				strbuf_addstr(sb, "tag: ");
 
-			strbuf_addstr(sb, decoration->name);
+			show_name(sb, decoration);
 
 			if (current_and_HEAD &&
 			    decoration->type == DECORATION_REF_HEAD) {
@@ -255,7 +266,7 @@ void format_decorations_extended(struct strbuf *sb,
 				strbuf_addstr(sb, " -> ");
 				strbuf_addstr(sb, color_reset);
 				strbuf_addstr(sb, decorate_get_color(use_color, current_and_HEAD->type));
-				strbuf_addstr(sb, current_and_HEAD->name);
+				show_name(sb, current_and_HEAD);
 			}
 			strbuf_addstr(sb, color_reset);
 
diff --git a/merge-recursive.c b/merge-recursive.c
index 1c9c30db6c..44d85bea4b 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -611,7 +611,6 @@ static char *unique_path(struct merge_options *o, const char *path, const char *
 {
 	struct strbuf newpath = STRBUF_INIT;
 	int suffix = 0;
-	struct stat st;
 	size_t base_len;
 
 	strbuf_addf(&newpath, "%s~", path);
@@ -620,7 +619,7 @@ static char *unique_path(struct merge_options *o, const char *path, const char *
 	base_len = newpath.len;
 	while (string_list_has_string(&o->current_file_set, newpath.buf) ||
 	       string_list_has_string(&o->current_directory_set, newpath.buf) ||
-	       lstat(newpath.buf, &st) == 0) {
+	       file_exists(newpath.buf)) {
 		strbuf_setlen(&newpath, base_len);
 		strbuf_addf(&newpath, "_%d", suffix++);
 	}
diff --git a/mergetools/winmerge b/mergetools/winmerge
new file mode 100644
index 0000000000..74a66d4e8d
--- /dev/null
+++ b/mergetools/winmerge
@@ -0,0 +1,36 @@
+diff_cmd () {
+	"$merge_tool_path" -u -e "$LOCAL" "$REMOTE"
+	return 0
+}
+
+merge_cmd () {
+	# mergetool.winmerge.trustExitCode is implicitly false.
+	# touch $BACKUP so that we can check_unchanged.
+	touch "$BACKUP"
+	"$merge_tool_path" -u -e -dl Local -dr Remote \
+		"$LOCAL" "$REMOTE" "$MERGED"
+	check_unchanged
+}
+
+translate_merge_tool_path() {
+	# Use WinMergeU.exe if it exists in $PATH
+	if type -p WinMergeU.exe >/dev/null 2>&1
+	then
+		printf WinMergeU.exe
+		return
+	fi
+
+	# Look for WinMergeU.exe in the typical locations
+	winmerge_exe="WinMerge/WinMergeU.exe"
+	for directory in $(env | grep -Ei '^PROGRAM(FILES(\(X86\))?|W6432)=' |
+		cut -d '=' -f 2- | sort -u)
+	do
+		if test -n "$directory" && test -x "$directory/$winmerge_exe"
+		then
+			printf '%s' "$directory/$winmerge_exe"
+			return
+		fi
+	done
+
+	printf WinMergeU.exe
+}
diff --git a/notes-merge.c b/notes-merge.c
index 109ff4ef41..0b2b82c41f 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -280,7 +280,7 @@ static void check_notes_merge_worktree(struct notes_merge_options *o)
 				    "(%s exists).", git_path("NOTES_MERGE_*"));
 		}
 
-		if (safe_create_leading_directories(git_path(
+		if (safe_create_leading_directories_const(git_path(
 				NOTES_MERGE_WORKTREE "/.test")))
 			die_errno("unable to create directory %s",
 				  git_path(NOTES_MERGE_WORKTREE));
@@ -295,8 +295,8 @@ static void write_buf_to_worktree(const unsigned char *obj,
 				  const char *buf, unsigned long size)
 {
 	int fd;
-	char *path = git_path(NOTES_MERGE_WORKTREE "/%s", sha1_to_hex(obj));
-	if (safe_create_leading_directories(path))
+	const char *path = git_path(NOTES_MERGE_WORKTREE "/%s", sha1_to_hex(obj));
+	if (safe_create_leading_directories_const(path))
 		die_errno("unable to create directory for '%s'", path);
 	if (file_exists(path))
 		die("found existing file at '%s'", path);
diff --git a/object.c b/object.c
index 23d6c96719..980ac5fcdf 100644
--- a/object.c
+++ b/object.c
@@ -41,7 +41,8 @@ int type_from_string_gently(const char *str, ssize_t len, int gentle)
 		len = strlen(str);
 
 	for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
-		if (!strncmp(str, object_type_strings[i], len))
+		if (!strncmp(str, object_type_strings[i], len) &&
+		    object_type_strings[i][len] == '\0')
 			return i;
 
 	if (gentle)
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 365f9d92ed..e5abb8a046 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -209,14 +209,12 @@ static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
 	return buffer[(*pos)++];
 }
 
+#define MAX_XOR_OFFSET 160
+
 static int load_bitmap_entries_v1(struct bitmap_index *index)
 {
-	static const size_t MAX_XOR_OFFSET = 160;
-
 	uint32_t i;
-	struct stored_bitmap **recent_bitmaps;
-
-	recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap));
+	struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
 
 	for (i = 0; i < index->entry_count; ++i) {
 		int xor_offset, flags;
@@ -986,6 +984,8 @@ void test_bitmap_walk(struct rev_info *revs)
 		fprintf(stderr, "OK!\n");
 	else
 		fprintf(stderr, "Mismatch!\n");
+
+	free(result);
 }
 
 static int rebuild_bitmap(uint32_t *reposition,
diff --git a/path.c b/path.c
index 595da81ca6..10f4cbf6b7 100644
--- a/path.c
+++ b/path.c
@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "strbuf.h"
 #include "string-list.h"
+#include "dir.h"
 
 static int get_st_mode_bits(const char *path, int *mode)
 {
@@ -16,11 +17,15 @@ static int get_st_mode_bits(const char *path, int *mode)
 
 static char bad_path[] = "/bad-path/";
 
-static char *get_pathname(void)
+static struct strbuf *get_pathname(void)
 {
-	static char pathname_array[4][PATH_MAX];
+	static struct strbuf pathname_array[4] = {
+		STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
+	};
 	static int index;
-	return pathname_array[3 & ++index];
+	struct strbuf *sb = &pathname_array[3 & ++index];
+	strbuf_reset(sb);
+	return sb;
 }
 
 static char *cleanup_path(char *path)
@@ -34,6 +39,13 @@ static char *cleanup_path(char *path)
 	return path;
 }
 
+static void strbuf_cleanup_path(struct strbuf *sb)
+{
+	char *path = cleanup_path(sb->buf);
+	if (path > sb->buf)
+		strbuf_remove(sb, 0, path - sb->buf);
+}
+
 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 {
 	va_list args;
@@ -49,152 +61,192 @@ char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 	return cleanup_path(buf);
 }
 
-static char *vsnpath(char *buf, size_t n, const char *fmt, va_list args)
+static int dir_prefix(const char *buf, const char *dir)
 {
-	const char *git_dir = get_git_dir();
-	size_t len;
+	int len = strlen(dir);
+	return !strncmp(buf, dir, len) &&
+		(is_dir_sep(buf[len]) || buf[len] == '\0');
+}
 
-	len = strlen(git_dir);
-	if (n < len + 1)
-		goto bad;
-	memcpy(buf, git_dir, len);
-	if (len && !is_dir_sep(git_dir[len-1]))
-		buf[len++] = '/';
-	len += vsnprintf(buf + len, n - len, fmt, args);
-	if (len >= n)
-		goto bad;
-	return cleanup_path(buf);
-bad:
-	strlcpy(buf, bad_path, n);
-	return buf;
+/* $buf =~ m|$dir/+$file| but without regex */
+static int is_dir_file(const char *buf, const char *dir, const char *file)
+{
+	int len = strlen(dir);
+	if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
+		return 0;
+	while (is_dir_sep(buf[len]))
+		len++;
+	return !strcmp(buf + len, file);
 }
 
-char *git_snpath(char *buf, size_t n, const char *fmt, ...)
+static void replace_dir(struct strbuf *buf, int len, const char *newdir)
 {
-	char *ret;
-	va_list args;
-	va_start(args, fmt);
-	ret = vsnpath(buf, n, fmt, args);
-	va_end(args);
-	return ret;
+	int newlen = strlen(newdir);
+	int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
+		!is_dir_sep(newdir[newlen - 1]);
+	if (need_sep)
+		len--;	 /* keep one char, to be replaced with '/'  */
+	strbuf_splice(buf, 0, len, newdir, newlen);
+	if (need_sep)
+		buf->buf[newlen] = '/';
 }
 
-char *git_pathdup(const char *fmt, ...)
+static const char *common_list[] = {
+	"/branches", "/hooks", "/info", "!/logs", "/lost-found",
+	"/objects", "/refs", "/remotes", "/worktrees", "/rr-cache", "/svn",
+	"config", "!gc.pid", "packed-refs", "shallow",
+	NULL
+};
+
+static void update_common_dir(struct strbuf *buf, int git_dir_len)
+{
+	char *base = buf->buf + git_dir_len;
+	const char **p;
+
+	if (is_dir_file(base, "logs", "HEAD") ||
+	    is_dir_file(base, "info", "sparse-checkout"))
+		return;	/* keep this in $GIT_DIR */
+	for (p = common_list; *p; p++) {
+		const char *path = *p;
+		int is_dir = 0;
+		if (*path == '!')
+			path++;
+		if (*path == '/') {
+			path++;
+			is_dir = 1;
+		}
+		if (is_dir && dir_prefix(base, path)) {
+			replace_dir(buf, git_dir_len, get_git_common_dir());
+			return;
+		}
+		if (!is_dir && !strcmp(base, path)) {
+			replace_dir(buf, git_dir_len, get_git_common_dir());
+			return;
+		}
+	}
+}
+
+void report_linked_checkout_garbage(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	const char **p;
+	int len;
+
+	if (!git_common_dir_env)
+		return;
+	strbuf_addf(&sb, "%s/", get_git_dir());
+	len = sb.len;
+	for (p = common_list; *p; p++) {
+		const char *path = *p;
+		if (*path == '!')
+			continue;
+		strbuf_setlen(&sb, len);
+		strbuf_addstr(&sb, path);
+		if (file_exists(sb.buf))
+			report_garbage("unused in linked checkout", sb.buf);
+	}
+	strbuf_release(&sb);
+}
+
+static void adjust_git_path(struct strbuf *buf, int git_dir_len)
+{
+	const char *base = buf->buf + git_dir_len;
+	if (git_graft_env && is_dir_file(base, "info", "grafts"))
+		strbuf_splice(buf, 0, buf->len,
+			      get_graft_file(), strlen(get_graft_file()));
+	else if (git_index_env && !strcmp(base, "index"))
+		strbuf_splice(buf, 0, buf->len,
+			      get_index_file(), strlen(get_index_file()));
+	else if (git_db_env && dir_prefix(base, "objects"))
+		replace_dir(buf, git_dir_len + 7, get_object_directory());
+	else if (git_common_dir_env)
+		update_common_dir(buf, git_dir_len);
+}
+
+static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
+{
+	int gitdir_len;
+	strbuf_addstr(buf, get_git_dir());
+	if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
+		strbuf_addch(buf, '/');
+	gitdir_len = buf->len;
+	strbuf_vaddf(buf, fmt, args);
+	adjust_git_path(buf, gitdir_len);
+	strbuf_cleanup_path(buf);
+}
+
+void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
 {
-	char path[PATH_MAX], *ret;
 	va_list args;
 	va_start(args, fmt);
-	ret = vsnpath(path, sizeof(path), fmt, args);
+	do_git_path(sb, fmt, args);
 	va_end(args);
-	return xstrdup(ret);
 }
 
-char *mkpathdup(const char *fmt, ...)
+const char *git_path(const char *fmt, ...)
 {
-	char *path;
-	struct strbuf sb = STRBUF_INIT;
+	struct strbuf *pathname = get_pathname();
 	va_list args;
-
 	va_start(args, fmt);
-	strbuf_vaddf(&sb, fmt, args);
+	do_git_path(pathname, fmt, args);
 	va_end(args);
-	path = xstrdup(cleanup_path(sb.buf));
-
-	strbuf_release(&sb);
-	return path;
+	return pathname->buf;
 }
 
-char *mkpath(const char *fmt, ...)
+char *git_pathdup(const char *fmt, ...)
 {
+	struct strbuf path = STRBUF_INIT;
 	va_list args;
-	unsigned len;
-	char *pathname = get_pathname();
-
 	va_start(args, fmt);
-	len = vsnprintf(pathname, PATH_MAX, fmt, args);
+	do_git_path(&path, fmt, args);
 	va_end(args);
-	if (len >= PATH_MAX)
-		return bad_path;
-	return cleanup_path(pathname);
+	return strbuf_detach(&path, NULL);
 }
 
-char *git_path(const char *fmt, ...)
+char *mkpathdup(const char *fmt, ...)
 {
-	char *pathname = get_pathname();
+	struct strbuf sb = STRBUF_INIT;
 	va_list args;
-	char *ret;
-
 	va_start(args, fmt);
-	ret = vsnpath(pathname, PATH_MAX, fmt, args);
+	strbuf_vaddf(&sb, fmt, args);
 	va_end(args);
-	return ret;
+	strbuf_cleanup_path(&sb);
+	return strbuf_detach(&sb, NULL);
 }
 
-void home_config_paths(char **global, char **xdg, char *file)
+const char *mkpath(const char *fmt, ...)
 {
-	char *xdg_home = getenv("XDG_CONFIG_HOME");
-	char *home = getenv("HOME");
-	char *to_free = NULL;
-
-	if (!home) {
-		if (global)
-			*global = NULL;
-	} else {
-		if (!xdg_home) {
-			to_free = mkpathdup("%s/.config", home);
-			xdg_home = to_free;
-		}
-		if (global)
-			*global = mkpathdup("%s/.gitconfig", home);
-	}
-
-	if (xdg) {
-		if (!xdg_home)
-			*xdg = NULL;
-		else
-			*xdg = mkpathdup("%s/git/%s", xdg_home, file);
-	}
-
-	free(to_free);
+	va_list args;
+	struct strbuf *pathname = get_pathname();
+	va_start(args, fmt);
+	strbuf_vaddf(pathname, fmt, args);
+	va_end(args);
+	return cleanup_path(pathname->buf);
 }
 
-char *git_path_submodule(const char *path, const char *fmt, ...)
+const char *git_path_submodule(const char *path, const char *fmt, ...)
 {
-	char *pathname = get_pathname();
-	struct strbuf buf = STRBUF_INIT;
+	struct strbuf *buf = get_pathname();
 	const char *git_dir;
 	va_list args;
-	unsigned len;
 
-	len = strlen(path);
-	if (len > PATH_MAX-100)
-		return bad_path;
+	strbuf_addstr(buf, path);
+	if (buf->len && buf->buf[buf->len - 1] != '/')
+		strbuf_addch(buf, '/');
+	strbuf_addstr(buf, ".git");
 
-	strbuf_addstr(&buf, path);
-	if (len && path[len-1] != '/')
-		strbuf_addch(&buf, '/');
-	strbuf_addstr(&buf, ".git");
-
-	git_dir = read_gitfile(buf.buf);
+	git_dir = read_gitfile(buf->buf);
 	if (git_dir) {
-		strbuf_reset(&buf);
-		strbuf_addstr(&buf, git_dir);
+		strbuf_reset(buf);
+		strbuf_addstr(buf, git_dir);
 	}
-	strbuf_addch(&buf, '/');
-
-	if (buf.len >= PATH_MAX)
-		return bad_path;
-	memcpy(pathname, buf.buf, buf.len + 1);
-
-	strbuf_release(&buf);
-	len = strlen(pathname);
+	strbuf_addch(buf, '/');
 
 	va_start(args, fmt);
-	len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
+	strbuf_vaddf(buf, fmt, args);
 	va_end(args);
-	if (len >= PATH_MAX)
-		return bad_path;
-	return cleanup_path(pathname);
+	strbuf_cleanup_path(buf);
+	return buf->buf;
 }
 
 int validate_headref(const char *path)
@@ -851,3 +903,18 @@ int is_ntfs_dotgit(const char *name)
 			len = -1;
 		}
 }
+
+char *xdg_config_home(const char *filename)
+{
+	const char *home, *config_home;
+
+	assert(filename);
+	config_home = getenv("XDG_CONFIG_HOME");
+	if (config_home && *config_home)
+		return mkpathdup("%s/git/%s", config_home, filename);
+
+	home = getenv("HOME");
+	if (home)
+		return mkpathdup("%s/.config/git/%s", home, filename);
+	return NULL;
+}
diff --git a/progress.c b/progress.c
index 412e6b1ecc..2e31bec60f 100644
--- a/progress.c
+++ b/progress.c
@@ -72,6 +72,12 @@ static void clear_progress_signal(void)
 	progress_update = 0;
 }
 
+static int is_foreground_fd(int fd)
+{
+	int tpgrp = tcgetpgrp(fd);
+	return tpgrp < 0 || tpgrp == getpgid(0);
+}
+
 static int display(struct progress *progress, unsigned n, const char *done)
 {
 	const char *eol, *tp;
@@ -98,16 +104,21 @@ static int display(struct progress *progress, unsigned n, const char *done)
 		unsigned percent = n * 100 / progress->total;
 		if (percent != progress->last_percent || progress_update) {
 			progress->last_percent = percent;
-			fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
-				progress->title, percent, n,
-				progress->total, tp, eol);
-			fflush(stderr);
+			if (is_foreground_fd(fileno(stderr)) || done) {
+				fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
+					progress->title, percent, n,
+					progress->total, tp, eol);
+				fflush(stderr);
+			}
 			progress_update = 0;
 			return 1;
 		}
 	} else if (progress_update) {
-		fprintf(stderr, "%s: %u%s%s", progress->title, n, tp, eol);
-		fflush(stderr);
+		if (is_foreground_fd(fileno(stderr)) || done) {
+			fprintf(stderr, "%s: %u%s%s",
+				progress->title, n, tp, eol);
+			fflush(stderr);
+		}
 		progress_update = 0;
 		return 1;
 	}
diff --git a/reachable.c b/reachable.c
index a647267ae9..69fa6851da 100644
--- a/reachable.c
+++ b/reachable.c
@@ -142,10 +142,12 @@ int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
 	data.revs = revs;
 	data.timestamp = timestamp;
 
-	r = for_each_loose_object(add_recent_loose, &data);
+	r = for_each_loose_object(add_recent_loose, &data,
+				  FOR_EACH_OBJECT_LOCAL_ONLY);
 	if (r)
 		return r;
-	return for_each_packed_object(add_recent_packed, &data);
+	return for_each_packed_object(add_recent_packed, &data,
+				      FOR_EACH_OBJECT_LOCAL_ONLY);
 }
 
 void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
diff --git a/read-cache.c b/read-cache.c
index 36ff89f29e..723d48dddf 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -39,11 +39,12 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,
 #define CACHE_EXT_TREE 0x54524545	/* "TREE" */
 #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
 #define CACHE_EXT_LINK 0x6c696e6b	  /* "link" */
+#define CACHE_EXT_UNTRACKED 0x554E5452	  /* "UNTR" */
 
 /* changes that can be kept in $GIT_DIR/index (basically all extensions) */
 #define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \
 		 CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \
-		 SPLIT_INDEX_ORDERED)
+		 SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED)
 
 struct index_state the_index;
 static const char *alternate_index_output;
@@ -79,6 +80,7 @@ void rename_index_entry_at(struct index_state *istate, int nr, const char *new_n
 	memcpy(new->name, new_name, namelen + 1);
 
 	cache_tree_invalidate_path(istate, old->name);
+	untracked_cache_remove_from_index(istate, old->name);
 	remove_index_entry_at(istate, nr);
 	add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
 }
@@ -270,20 +272,34 @@ static int ce_match_stat_basic(const struct cache_entry *ce, struct stat *st)
 	return changed;
 }
 
-static int is_racy_timestamp(const struct index_state *istate,
-			     const struct cache_entry *ce)
+static int is_racy_stat(const struct index_state *istate,
+			const struct stat_data *sd)
 {
-	return (!S_ISGITLINK(ce->ce_mode) &&
-		istate->timestamp.sec &&
+	return (istate->timestamp.sec &&
 #ifdef USE_NSEC
 		 /* nanosecond timestamped files can also be racy! */
-		(istate->timestamp.sec < ce->ce_stat_data.sd_mtime.sec ||
-		 (istate->timestamp.sec == ce->ce_stat_data.sd_mtime.sec &&
-		  istate->timestamp.nsec <= ce->ce_stat_data.sd_mtime.nsec))
+		(istate->timestamp.sec < sd->sd_mtime.sec ||
+		 (istate->timestamp.sec == sd->sd_mtime.sec &&
+		  istate->timestamp.nsec <= sd->sd_mtime.nsec))
 #else
-		istate->timestamp.sec <= ce->ce_stat_data.sd_mtime.sec
+		istate->timestamp.sec <= sd->sd_mtime.sec
 #endif
-		 );
+		);
+}
+
+static int is_racy_timestamp(const struct index_state *istate,
+			     const struct cache_entry *ce)
+{
+	return (!S_ISGITLINK(ce->ce_mode) &&
+		is_racy_stat(istate, &ce->ce_stat_data));
+}
+
+int match_stat_data_racy(const struct index_state *istate,
+			 const struct stat_data *sd, struct stat *st)
+{
+	if (is_racy_stat(istate, sd))
+		return MTIME_CHANGED;
+	return match_stat_data(sd, st);
 }
 
 int ie_match_stat(const struct index_state *istate,
@@ -538,6 +554,7 @@ int remove_file_from_index(struct index_state *istate, const char *path)
 	if (pos < 0)
 		pos = -pos-1;
 	cache_tree_invalidate_path(istate, path);
+	untracked_cache_remove_from_index(istate, path);
 	while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
 		remove_index_entry_at(istate, pos);
 	return 0;
@@ -982,6 +999,8 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
 	}
 	pos = -pos-1;
 
+	untracked_cache_add_to_index(istate, ce->name);
+
 	/*
 	 * Inserting a merged entry ("stage 0") into the index
 	 * will always replace all non-merged entries..
@@ -1372,6 +1391,9 @@ static int read_index_extension(struct index_state *istate,
 		if (read_link_extension(istate, data, sz))
 			return -1;
 		break;
+	case CACHE_EXT_UNTRACKED:
+		istate->untracked = read_untracked_extension(data, sz);
+		break;
 	default:
 		if (*ext < 'A' || 'Z' < *ext)
 			return error("index uses %.4s extension, which we do not understand",
@@ -1667,6 +1689,8 @@ int discard_index(struct index_state *istate)
 	istate->cache = NULL;
 	istate->cache_alloc = 0;
 	discard_split_index(istate);
+	free_untracked_cache(istate->untracked);
+	istate->untracked = NULL;
 	return 0;
 }
 
@@ -2053,6 +2077,17 @@ static int do_write_index(struct index_state *istate, int newfd,
 		if (err)
 			return -1;
 	}
+	if (!strip_extensions && istate->untracked) {
+		struct strbuf sb = STRBUF_INIT;
+
+		write_untracked_extension(&sb, istate->untracked);
+		err = write_index_ext_header(&c, newfd, CACHE_EXT_UNTRACKED,
+					     sb.len) < 0 ||
+			ce_write(&c, newfd, sb.buf, sb.len) < 0;
+		strbuf_release(&sb);
+		if (err)
+			return -1;
+	}
 
 	if (ce_flush(&c, newfd, istate->sha1) || fstat(newfd, &st))
 		return -1;
diff --git a/refs.c b/refs.c
index 47e4e5380a..8480d8dbf5 100644
--- a/refs.c
+++ b/refs.c
@@ -11,7 +11,6 @@ struct ref_lock {
 	char *orig_ref_name;
 	struct lock_file *lk;
 	unsigned char old_sha1[20];
-	int lock_fd;
 };
 
 /*
@@ -57,6 +56,12 @@ static unsigned char refname_disposition[256] = {
  */
 #define REF_HAVE_OLD	0x10
 
+/*
+ * Used as a flag in ref_update::flags when the lockfile needs to be
+ * committed.
+ */
+#define REF_NEEDS_COMMIT 0x20
+
 /*
  * Try to read one refname component from the front of refname.
  * Return the length of the component found, or -1 if the component is
@@ -263,7 +268,7 @@ struct ref_dir {
  * presence of an empty subdirectory does not block the creation of a
  * similarly-named reference.  (The fact that reference names with the
  * same leading components can conflict *with each other* is a
- * separate issue that is regulated by is_refname_available().)
+ * separate issue that is regulated by verify_refname_available().)
  *
  * Please note that the name field contains the fully-qualified
  * reference (or subdirectory) name.  Space could be saved by only
@@ -344,8 +349,6 @@ static struct ref_entry *create_ref_entry(const char *refname,
 	if (check_name &&
 	    check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
 		die("Reference has invalid format: '%s'", refname);
-	if (!check_name && !refname_is_safe(refname))
-		die("Reference has invalid name: '%s'", refname);
 	len = strlen(refname) + 1;
 	ref = xmalloc(sizeof(struct ref_entry) + len);
 	hashcpy(ref->u.value.sha1, sha1);
@@ -841,121 +844,181 @@ static void prime_ref_dir(struct ref_dir *dir)
 	}
 }
 
-static int entry_matches(struct ref_entry *entry, const struct string_list *list)
-{
-	return list && string_list_has_string(list, entry->name);
-}
-
 struct nonmatching_ref_data {
 	const struct string_list *skip;
-	struct ref_entry *found;
+	const char *conflicting_refname;
 };
 
 static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
 {
 	struct nonmatching_ref_data *data = vdata;
 
-	if (entry_matches(entry, data->skip))
+	if (data->skip && string_list_has_string(data->skip, entry->name))
 		return 0;
 
-	data->found = entry;
+	data->conflicting_refname = entry->name;
 	return 1;
 }
 
-static void report_refname_conflict(struct ref_entry *entry,
-				    const char *refname)
-{
-	error("'%s' exists; cannot create '%s'", entry->name, refname);
-}
-
 /*
- * Return true iff a reference named refname could be created without
- * conflicting with the name of an existing reference in dir.  If
- * skip is non-NULL, ignore potential conflicts with refs in skip
- * (e.g., because they are scheduled for deletion in the same
- * operation).
+ * Return 0 if a reference named refname could be created without
+ * conflicting with the name of an existing reference in dir.
+ * Otherwise, return a negative value and write an explanation to err.
+ * If extras is non-NULL, it is a list of additional refnames with
+ * which refname is not allowed to conflict. If skip is non-NULL,
+ * ignore potential conflicts with refs in skip (e.g., because they
+ * are scheduled for deletion in the same operation). Behavior is
+ * undefined if the same name is listed in both extras and skip.
  *
  * Two reference names conflict if one of them exactly matches the
- * leading components of the other; e.g., "foo/bar" conflicts with
- * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
- * "foo/barbados".
+ * leading components of the other; e.g., "refs/foo/bar" conflicts
+ * with both "refs/foo" and with "refs/foo/bar/baz" but not with
+ * "refs/foo/bar" or "refs/foo/barbados".
  *
- * skip must be sorted.
+ * extras and skip must be sorted.
  */
-static int is_refname_available(const char *refname,
-				const struct string_list *skip,
-				struct ref_dir *dir)
+static int verify_refname_available(const char *refname,
+				    const struct string_list *extras,
+				    const struct string_list *skip,
+				    struct ref_dir *dir,
+				    struct strbuf *err)
 {
 	const char *slash;
-	size_t len;
 	int pos;
-	char *dirname;
+	struct strbuf dirname = STRBUF_INIT;
+	int ret = -1;
+
+	/*
+	 * For the sake of comments in this function, suppose that
+	 * refname is "refs/foo/bar".
+	 */
 
+	assert(err);
+
+	strbuf_grow(&dirname, strlen(refname) + 1);
 	for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
+		/* Expand dirname to the new prefix, not including the trailing slash: */
+		strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
+
 		/*
-		 * We are still at a leading dir of the refname; we are
-		 * looking for a conflict with a leaf entry.
-		 *
-		 * If we find one, we still must make sure it is
-		 * not in "skip".
+		 * We are still at a leading dir of the refname (e.g.,
+		 * "refs/foo"; if there is a reference with that name,
+		 * it is a conflict, *unless* it is in skip.
 		 */
-		pos = search_ref_dir(dir, refname, slash - refname);
-		if (pos >= 0) {
-			struct ref_entry *entry = dir->entries[pos];
-			if (entry_matches(entry, skip))
-				return 1;
-			report_refname_conflict(entry, refname);
-			return 0;
+		if (dir) {
+			pos = search_ref_dir(dir, dirname.buf, dirname.len);
+			if (pos >= 0 &&
+			    (!skip || !string_list_has_string(skip, dirname.buf))) {
+				/*
+				 * We found a reference whose name is
+				 * a proper prefix of refname; e.g.,
+				 * "refs/foo", and is not in skip.
+				 */
+				strbuf_addf(err, "'%s' exists; cannot create '%s'",
+					    dirname.buf, refname);
+				goto cleanup;
+			}
 		}
 
+		if (extras && string_list_has_string(extras, dirname.buf) &&
+		    (!skip || !string_list_has_string(skip, dirname.buf))) {
+			strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+				    refname, dirname.buf);
+			goto cleanup;
+		}
 
 		/*
 		 * Otherwise, we can try to continue our search with
-		 * the next component; if we come up empty, we know
-		 * there is nothing under this whole prefix.
+		 * the next component. So try to look up the
+		 * directory, e.g., "refs/foo/". If we come up empty,
+		 * we know there is nothing under this whole prefix,
+		 * but even in that case we still have to continue the
+		 * search for conflicts with extras.
 		 */
-		pos = search_ref_dir(dir, refname, slash + 1 - refname);
-		if (pos < 0)
-			return 1;
-
-		dir = get_ref_dir(dir->entries[pos]);
+		strbuf_addch(&dirname, '/');
+		if (dir) {
+			pos = search_ref_dir(dir, dirname.buf, dirname.len);
+			if (pos < 0) {
+				/*
+				 * There was no directory "refs/foo/",
+				 * so there is nothing under this
+				 * whole prefix. So there is no need
+				 * to continue looking for conflicting
+				 * references. But we need to continue
+				 * looking for conflicting extras.
+				 */
+				dir = NULL;
+			} else {
+				dir = get_ref_dir(dir->entries[pos]);
+			}
+		}
 	}
 
 	/*
-	 * We are at the leaf of our refname; we want to
-	 * make sure there are no directories which match it.
+	 * We are at the leaf of our refname (e.g., "refs/foo/bar").
+	 * There is no point in searching for a reference with that
+	 * name, because a refname isn't considered to conflict with
+	 * itself. But we still need to check for references whose
+	 * names are in the "refs/foo/bar/" namespace, because they
+	 * *do* conflict.
 	 */
-	len = strlen(refname);
-	dirname = xmallocz(len + 1);
-	sprintf(dirname, "%s/", refname);
-	pos = search_ref_dir(dir, dirname, len + 1);
-	free(dirname);
+	strbuf_addstr(&dirname, refname + dirname.len);
+	strbuf_addch(&dirname, '/');
+
+	if (dir) {
+		pos = search_ref_dir(dir, dirname.buf, dirname.len);
+
+		if (pos >= 0) {
+			/*
+			 * We found a directory named "$refname/"
+			 * (e.g., "refs/foo/bar/"). It is a problem
+			 * iff it contains any ref that is not in
+			 * "skip".
+			 */
+			struct nonmatching_ref_data data;
+
+			data.skip = skip;
+			data.conflicting_refname = NULL;
+			dir = get_ref_dir(dir->entries[pos]);
+			sort_ref_dir(dir);
+			if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
+				strbuf_addf(err, "'%s' exists; cannot create '%s'",
+					    data.conflicting_refname, refname);
+				goto cleanup;
+			}
+		}
+	}
 
-	if (pos >= 0) {
+	if (extras) {
 		/*
-		 * We found a directory named "refname". It is a
-		 * problem iff it contains any ref that is not
-		 * in "skip".
+		 * Check for entries in extras that start with
+		 * "$refname/". We do that by looking for the place
+		 * where "$refname/" would be inserted in extras. If
+		 * there is an entry at that position that starts with
+		 * "$refname/" and is not in skip, then we have a
+		 * conflict.
 		 */
-		struct ref_entry *entry = dir->entries[pos];
-		struct ref_dir *dir = get_ref_dir(entry);
-		struct nonmatching_ref_data data;
+		for (pos = string_list_find_insert_index(extras, dirname.buf, 0);
+		     pos < extras->nr; pos++) {
+			const char *extra_refname = extras->items[pos].string;
 
-		data.skip = skip;
-		sort_ref_dir(dir);
-		if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data))
-			return 1;
+			if (!starts_with(extra_refname, dirname.buf))
+				break;
 
-		report_refname_conflict(data.found, refname);
-		return 0;
+			if (!skip || !string_list_has_string(skip, extra_refname)) {
+				strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+					    refname, extra_refname);
+				goto cleanup;
+			}
+		}
 	}
 
-	/*
-	 * There is no point in searching for another leaf
-	 * node which matches it; such an entry would be the
-	 * ref we are looking for, not a conflict.
-	 */
-	return 1;
+	/* No conflicts were found */
+	ret = 0;
+
+cleanup:
+	strbuf_release(&dirname);
+	return ret;
 }
 
 struct packed_ref_cache {
@@ -1178,6 +1241,8 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
 			int flag = REF_ISPACKED;
 
 			if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+				if (!refname_is_safe(refname))
+					die("packed refname is dangerous: %s", refname);
 				hashclr(sha1);
 				flag |= REF_BAD_NAME | REF_ISBROKEN;
 			}
@@ -1323,6 +1388,8 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir)
 			}
 			if (check_refname_format(refname.buf,
 						 REFNAME_ALLOW_ONELEVEL)) {
+				if (!refname_is_safe(refname.buf))
+					die("loose refname is dangerous: %s", refname.buf);
 				hashclr(sha1);
 				flag |= REF_BAD_NAME | REF_ISBROKEN;
 			}
@@ -1382,7 +1449,7 @@ static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
 {
 	int fd, len;
 	char buffer[128], *p;
-	char *path;
+	const char *path;
 
 	if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
 		return -1;
@@ -1475,7 +1542,11 @@ static int resolve_missing_loose_ref(const char *refname,
 }
 
 /* This function needs to return a meaningful errno on failure */
-const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
+static const char *resolve_ref_unsafe_1(const char *refname,
+					int resolve_flags,
+					unsigned char *sha1,
+					int *flags,
+					struct strbuf *sb_path)
 {
 	int depth = MAXDEPTH;
 	ssize_t len;
@@ -1506,7 +1577,7 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
 		bad_name = 1;
 	}
 	for (;;) {
-		char path[PATH_MAX];
+		const char *path;
 		struct stat st;
 		char *buf;
 		int fd;
@@ -1516,7 +1587,9 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
 			return NULL;
 		}
 
-		git_snpath(path, sizeof(path), "%s", refname);
+		strbuf_reset(sb_path);
+		strbuf_git_path(sb_path, "%s", refname);
+		path = sb_path->buf;
 
 		/*
 		 * We might have to loop back here to avoid a race
@@ -1643,6 +1716,16 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
 	}
 }
 
+const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
+			       unsigned char *sha1, int *flags)
+{
+	struct strbuf sb_path = STRBUF_INIT;
+	const char *ret = resolve_ref_unsafe_1(refname, resolve_flags,
+					       sha1, flags, &sb_path);
+	strbuf_release(&sb_path);
+	return ret;
+}
+
 char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)
 {
 	return xstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags));
@@ -2271,10 +2354,12 @@ int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
  */
 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 					    const unsigned char *old_sha1,
+					    const struct string_list *extras,
 					    const struct string_list *skip,
-					    unsigned int flags, int *type_p)
+					    unsigned int flags, int *type_p,
+					    struct strbuf *err)
 {
-	char *ref_file;
+	const char *ref_file;
 	const char *orig_refname = refname;
 	struct ref_lock *lock;
 	int last_errno = 0;
@@ -2283,8 +2368,9 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	int resolve_flags = 0;
 	int attempts_remaining = 3;
 
+	assert(err);
+
 	lock = xcalloc(1, sizeof(struct ref_lock));
-	lock->lock_fd = -1;
 
 	if (mustexist)
 		resolve_flags |= RESOLVE_REF_READING;
@@ -2305,7 +2391,12 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 		ref_file = git_path("%s", orig_refname);
 		if (remove_empty_directories(ref_file)) {
 			last_errno = errno;
-			error("there are still refs under '%s'", orig_refname);
+
+			if (!verify_refname_available(orig_refname, extras, skip,
+						      get_loose_refs(&ref_cache), err))
+				strbuf_addf(err, "there are still refs under '%s'",
+					    orig_refname);
+
 			goto error_return;
 		}
 		refname = resolve_ref_unsafe(orig_refname, resolve_flags,
@@ -2315,8 +2406,12 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	    *type_p = type;
 	if (!refname) {
 		last_errno = errno;
-		error("unable to resolve reference %s: %s",
-			orig_refname, strerror(errno));
+		if (last_errno != ENOTDIR ||
+		    !verify_refname_available(orig_refname, extras, skip,
+					      get_loose_refs(&ref_cache), err))
+			strbuf_addf(err, "unable to resolve reference %s: %s",
+				    orig_refname, strerror(last_errno));
+
 		goto error_return;
 	}
 	/*
@@ -2326,7 +2421,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	 * our refname.
 	 */
 	if (is_null_sha1(lock->old_sha1) &&
-	     !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {
+	    verify_refname_available(refname, extras, skip,
+				     get_packed_refs(&ref_cache), err)) {
 		last_errno = ENOTDIR;
 		goto error_return;
 	}
@@ -2343,7 +2439,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	ref_file = git_path("%s", refname);
 
  retry:
-	switch (safe_create_leading_directories(ref_file)) {
+	switch (safe_create_leading_directories_const(ref_file)) {
 	case SCLD_OK:
 		break; /* success */
 	case SCLD_VANISHED:
@@ -2352,12 +2448,11 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 		/* fall through */
 	default:
 		last_errno = errno;
-		error("unable to create directory for %s", ref_file);
+		strbuf_addf(err, "unable to create directory for %s", ref_file);
 		goto error_return;
 	}
 
-	lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
-	if (lock->lock_fd < 0) {
+	if (hold_lock_file_for_update(lock->lk, ref_file, lflags) < 0) {
 		last_errno = errno;
 		if (errno == ENOENT && --attempts_remaining > 0)
 			/*
@@ -2367,10 +2462,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 			 */
 			goto retry;
 		else {
-			struct strbuf err = STRBUF_INIT;
-			unable_to_lock_message(ref_file, errno, &err);
-			error("%s", err.buf);
-			strbuf_release(&err);
+			unable_to_lock_message(ref_file, errno, err);
 			goto error_return;
 		}
 	}
@@ -2413,9 +2505,19 @@ static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
 /* This should return a meaningful errno on failure */
 int lock_packed_refs(int flags)
 {
+	static int timeout_configured = 0;
+	static int timeout_value = 1000;
+
 	struct packed_ref_cache *packed_ref_cache;
 
-	if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
+	if (!timeout_configured) {
+		git_config_get_int("core.packedrefstimeout", &timeout_value);
+		timeout_configured = 1;
+	}
+
+	if (hold_lock_file_for_update_timeout(
+			    &packlock, git_path("packed-refs"),
+			    flags, timeout_value) < 0)
 		return -1;
 	/*
 	 * Get the current packed-refs while holding the lock.  If the
@@ -2721,7 +2823,7 @@ static int rename_tmp_log(const char *newrefname)
 	int attempts_remaining = 4;
 
  retry:
-	switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
+	switch (safe_create_leading_directories_const(git_path("logs/%s", newrefname))) {
 	case SCLD_OK:
 		break; /* success */
 	case SCLD_VANISHED:
@@ -2764,17 +2866,25 @@ static int rename_tmp_log(const char *newrefname)
 static int rename_ref_available(const char *oldname, const char *newname)
 {
 	struct string_list skip = STRING_LIST_INIT_NODUP;
+	struct strbuf err = STRBUF_INIT;
 	int ret;
 
 	string_list_insert(&skip, oldname);
-	ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))
-	    && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));
+	ret = !verify_refname_available(newname, NULL, &skip,
+					get_packed_refs(&ref_cache), &err)
+		&& !verify_refname_available(newname, NULL, &skip,
+					     get_loose_refs(&ref_cache), &err);
+	if (!ret)
+		error("%s", err.buf);
+
 	string_list_clear(&skip, 0);
+	strbuf_release(&err);
 	return ret;
 }
 
-static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,
-			  const char *logmsg);
+static int write_ref_to_lockfile(struct ref_lock *lock, const unsigned char *sha1);
+static int commit_ref_update(struct ref_lock *lock,
+			     const unsigned char *sha1, const char *logmsg);
 
 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
 {
@@ -2784,6 +2894,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 	struct stat loginfo;
 	int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
 	const char *symref = NULL;
+	struct strbuf err = STRBUF_INIT;
 
 	if (log && S_ISLNK(loginfo.st_mode))
 		return error("reflog for %s is a symlink", oldrefname);
@@ -2826,13 +2937,16 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 
 	logmoved = log;
 
-	lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);
+	lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);
 	if (!lock) {
-		error("unable to lock %s for update", newrefname);
+		error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
+		strbuf_release(&err);
 		goto rollback;
 	}
 	hashcpy(lock->old_sha1, orig_sha1);
-	if (write_ref_sha1(lock, orig_sha1, logmsg)) {
+
+	if (write_ref_to_lockfile(lock, orig_sha1) ||
+	    commit_ref_update(lock, orig_sha1, logmsg)) {
 		error("unable to write current sha1 into %s", newrefname);
 		goto rollback;
 	}
@@ -2840,15 +2954,17 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 	return 0;
 
  rollback:
-	lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);
+	lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);
 	if (!lock) {
-		error("unable to lock %s for rollback", oldrefname);
+		error("unable to lock %s for rollback: %s", oldrefname, err.buf);
+		strbuf_release(&err);
 		goto rollbacklog;
 	}
 
 	flag = log_all_ref_updates;
 	log_all_ref_updates = 0;
-	if (write_ref_sha1(lock, orig_sha1, NULL))
+	if (write_ref_to_lockfile(lock, orig_sha1) ||
+	    commit_ref_update(lock, orig_sha1, NULL))
 		error("unable to write current sha1 into %s", oldrefname);
 	log_all_ref_updates = flag;
 
@@ -2868,7 +2984,6 @@ static int close_ref(struct ref_lock *lock)
 {
 	if (close_lock_file(lock->lk))
 		return -1;
-	lock->lock_fd = -1;
 	return 0;
 }
 
@@ -2876,7 +2991,6 @@ static int commit_ref(struct ref_lock *lock)
 {
 	if (commit_lock_file(lock->lk))
 		return -1;
-	lock->lock_fd = -1;
 	return 0;
 }
 
@@ -2907,11 +3021,15 @@ static int copy_msg(char *buf, const char *msg)
 }
 
 /* This function must set a meaningful errno on failure */
-int log_ref_setup(const char *refname, char *logfile, int bufsize)
+int log_ref_setup(const char *refname, struct strbuf *sb_logfile)
 {
 	int logfd, oflags = O_APPEND | O_WRONLY;
+	char *logfile;
 
-	git_snpath(logfile, bufsize, "logs/%s", refname);
+	strbuf_git_path(sb_logfile, "logs/%s", refname);
+	logfile = sb_logfile->buf;
+	/* make sure the rest of the function can't change "logfile" */
+	sb_logfile = NULL;
 	if (log_all_ref_updates &&
 	    (starts_with(refname, "refs/heads/") ||
 	     starts_with(refname, "refs/remotes/") ||
@@ -2982,18 +3100,22 @@ static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
 	return 0;
 }
 
-static int log_ref_write(const char *refname, const unsigned char *old_sha1,
-			 const unsigned char *new_sha1, const char *msg)
+static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,
+			   const unsigned char *new_sha1, const char *msg,
+			   struct strbuf *sb_log_file)
 {
 	int logfd, result, oflags = O_APPEND | O_WRONLY;
-	char log_file[PATH_MAX];
+	char *log_file;
 
 	if (log_all_ref_updates < 0)
 		log_all_ref_updates = !is_bare_repository();
 
-	result = log_ref_setup(refname, log_file, sizeof(log_file));
+	result = log_ref_setup(refname, sb_log_file);
 	if (result)
 		return result;
+	log_file = sb_log_file->buf;
+	/* make sure the rest of the function can't change "log_file" */
+	sb_log_file = NULL;
 
 	logfd = open(log_file, oflags);
 	if (logfd < 0)
@@ -3016,17 +3138,26 @@ static int log_ref_write(const char *refname, const unsigned char *old_sha1,
 	return 0;
 }
 
+static int log_ref_write(const char *refname, const unsigned char *old_sha1,
+			 const unsigned char *new_sha1, const char *msg)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb);
+	strbuf_release(&sb);
+	return ret;
+}
+
 int is_branch(const char *refname)
 {
 	return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 }
 
 /*
- * Write sha1 into the ref specified by the lock. Make sure that errno
- * is sane on error.
+ * Write sha1 into the open lockfile, then close the lockfile. On
+ * errors, rollback the lockfile and set errno to reflect the problem.
  */
-static int write_ref_sha1(struct ref_lock *lock,
-	const unsigned char *sha1, const char *logmsg)
+static int write_ref_to_lockfile(struct ref_lock *lock,
+				 const unsigned char *sha1)
 {
 	static char term = '\n';
 	struct object *o;
@@ -3046,8 +3177,8 @@ static int write_ref_sha1(struct ref_lock *lock,
 		errno = EINVAL;
 		return -1;
 	}
-	if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
-	    write_in_full(lock->lock_fd, &term, 1) != 1 ||
+	if (write_in_full(lock->lk->fd, sha1_to_hex(sha1), 40) != 40 ||
+	    write_in_full(lock->lk->fd, &term, 1) != 1 ||
 	    close_ref(lock) < 0) {
 		int save_errno = errno;
 		error("Couldn't write %s", lock->lk->filename.buf);
@@ -3055,6 +3186,17 @@ static int write_ref_sha1(struct ref_lock *lock,
 		errno = save_errno;
 		return -1;
 	}
+	return 0;
+}
+
+/*
+ * Commit a change to a loose reference that has already been written
+ * to the loose reference lockfile. Also update the reflogs if
+ * necessary, using the specified lockmsg (which can be NULL).
+ */
+static int commit_ref_update(struct ref_lock *lock,
+			     const unsigned char *sha1, const char *logmsg)
+{
 	clear_loose_ref_cache(&ref_cache);
 	if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
 	    (strcmp(lock->ref_name, lock->orig_ref_name) &&
@@ -3695,25 +3837,18 @@ int update_ref(const char *msg, const char *refname,
 	return 0;
 }
 
-static int ref_update_compare(const void *r1, const void *r2)
-{
-	const struct ref_update * const *u1 = r1;
-	const struct ref_update * const *u2 = r2;
-	return strcmp((*u1)->refname, (*u2)->refname);
-}
-
-static int ref_update_reject_duplicates(struct ref_update **updates, int n,
+static int ref_update_reject_duplicates(struct string_list *refnames,
 					struct strbuf *err)
 {
-	int i;
+	int i, n = refnames->nr;
 
 	assert(err);
 
 	for (i = 1; i < n; i++)
-		if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
+		if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
 			strbuf_addf(err,
 				    "Multiple updates for ref '%s' not allowed.",
-				    updates[i]->refname);
+				    refnames->items[i].string);
 			return 1;
 		}
 	return 0;
@@ -3727,6 +3862,7 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 	struct ref_update **updates = transaction->updates;
 	struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
 	struct string_list_item *ref_to_delete;
+	struct string_list affected_refnames = STRING_LIST_INIT_NODUP;
 
 	assert(err);
 
@@ -3738,63 +3874,101 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		return 0;
 	}
 
-	/* Copy, sort, and reject duplicate refs */
-	qsort(updates, n, sizeof(*updates), ref_update_compare);
-	if (ref_update_reject_duplicates(updates, n, err)) {
+	/* Fail if a refname appears more than once in the transaction: */
+	for (i = 0; i < n; i++)
+		string_list_append(&affected_refnames, updates[i]->refname);
+	string_list_sort(&affected_refnames);
+	if (ref_update_reject_duplicates(&affected_refnames, err)) {
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
 	}
 
-	/* Acquire all locks while verifying old values */
+	/*
+	 * Acquire all locks, verify old values if provided, check
+	 * that new values are valid, and write new values to the
+	 * lockfiles, ready to be activated. Only keep one lockfile
+	 * open at a time to avoid running out of file descriptors.
+	 */
 	for (i = 0; i < n; i++) {
 		struct ref_update *update = updates[i];
-		unsigned int flags = update->flags;
 
-		if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
-			flags |= REF_DELETING;
+		if ((update->flags & REF_HAVE_NEW) &&
+		    is_null_sha1(update->new_sha1))
+			update->flags |= REF_DELETING;
 		update->lock = lock_ref_sha1_basic(
 				update->refname,
 				((update->flags & REF_HAVE_OLD) ?
 				 update->old_sha1 : NULL),
-				NULL,
-				flags,
-				&update->type);
+				&affected_refnames, NULL,
+				update->flags,
+				&update->type,
+				err);
 		if (!update->lock) {
+			char *reason;
+
 			ret = (errno == ENOTDIR)
 				? TRANSACTION_NAME_CONFLICT
 				: TRANSACTION_GENERIC_ERROR;
-			strbuf_addf(err, "Cannot lock the ref '%s'.",
-				    update->refname);
+			reason = strbuf_detach(err, NULL);
+			strbuf_addf(err, "Cannot lock ref '%s': %s",
+				    update->refname, reason);
+			free(reason);
 			goto cleanup;
 		}
-	}
-
-	/* Perform updates first so live commits remain referenced */
-	for (i = 0; i < n; i++) {
-		struct ref_update *update = updates[i];
-		int flags = update->flags;
-
-		if ((flags & REF_HAVE_NEW) && !is_null_sha1(update->new_sha1)) {
+		if ((update->flags & REF_HAVE_NEW) &&
+		    !(update->flags & REF_DELETING)) {
 			int overwriting_symref = ((update->type & REF_ISSYMREF) &&
 						  (update->flags & REF_NODEREF));
 
-			if (!overwriting_symref
-			    && !hashcmp(update->lock->old_sha1, update->new_sha1)) {
+			if (!overwriting_symref &&
+			    !hashcmp(update->lock->old_sha1, update->new_sha1)) {
 				/*
 				 * The reference already has the desired
 				 * value, so we don't need to write it.
 				 */
-				unlock_ref(update->lock);
+			} else if (write_ref_to_lockfile(update->lock,
+							 update->new_sha1)) {
+				/*
+				 * The lock was freed upon failure of
+				 * write_ref_to_lockfile():
+				 */
+				update->lock = NULL;
+				strbuf_addf(err, "Cannot update the ref '%s'.",
+					    update->refname);
+				ret = TRANSACTION_GENERIC_ERROR;
+				goto cleanup;
+			} else {
+				update->flags |= REF_NEEDS_COMMIT;
+			}
+		}
+		if (!(update->flags & REF_NEEDS_COMMIT)) {
+			/*
+			 * We didn't have to write anything to the lockfile.
+			 * Close it to free up the file descriptor:
+			 */
+			if (close_ref(update->lock)) {
+				strbuf_addf(err, "Couldn't close %s.lock",
+					    update->refname);
+				goto cleanup;
+			}
+		}
+	}
+
+	/* Perform updates first so live commits remain referenced */
+	for (i = 0; i < n; i++) {
+		struct ref_update *update = updates[i];
+
+		if (update->flags & REF_NEEDS_COMMIT) {
+			if (commit_ref_update(update->lock,
+					      update->new_sha1, update->msg)) {
+				/* freed by commit_ref_update(): */
 				update->lock = NULL;
-			} else if (write_ref_sha1(update->lock, update->new_sha1,
-						  update->msg)) {
-				update->lock = NULL; /* freed by write_ref_sha1 */
 				strbuf_addf(err, "Cannot update the ref '%s'.",
 					    update->refname);
 				ret = TRANSACTION_GENERIC_ERROR;
 				goto cleanup;
 			} else {
-				/* freed by write_ref_sha1(): */
+				/* freed by commit_ref_update(): */
 				update->lock = NULL;
 			}
 		}
@@ -3803,15 +3977,14 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 	/* Perform deletes now that updates are safely completed */
 	for (i = 0; i < n; i++) {
 		struct ref_update *update = updates[i];
-		int flags = update->flags;
 
-		if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) {
+		if (update->flags & REF_DELETING) {
 			if (delete_ref_loose(update->lock, update->type, err)) {
 				ret = TRANSACTION_GENERIC_ERROR;
 				goto cleanup;
 			}
 
-			if (!(flags & REF_ISPRUNING))
+			if (!(update->flags & REF_ISPRUNING))
 				string_list_append(&refs_to_delete,
 						   update->lock->ref_name);
 		}
@@ -3832,6 +4005,7 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		if (updates[i]->lock)
 			unlock_ref(updates[i]->lock);
 	string_list_clear(&refs_to_delete, 0);
+	string_list_clear(&affected_refnames, 0);
 	return ret;
 }
 
@@ -4021,6 +4195,7 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 	char *log_file;
 	int status = 0;
 	int type;
+	struct strbuf err = STRBUF_INIT;
 
 	memset(&cb, 0, sizeof(cb));
 	cb.flags = flags;
@@ -4032,9 +4207,12 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 	 * reference itself, plus we might need to update the
 	 * reference if --updateref was specified:
 	 */
-	lock = lock_ref_sha1_basic(refname, sha1, NULL, 0, &type);
-	if (!lock)
-		return error("cannot lock ref '%s'", refname);
+	lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err);
+	if (!lock) {
+		error("cannot lock ref '%s': %s", refname, err.buf);
+		strbuf_release(&err);
+		return -1;
+	}
 	if (!reflog_exists(refname)) {
 		unlock_ref(lock);
 		return 0;
@@ -4084,9 +4262,9 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 			status |= error("couldn't write %s: %s", log_file,
 					strerror(errno));
 		} else if (update &&
-			(write_in_full(lock->lock_fd,
+			   (write_in_full(lock->lk->fd,
 				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
-			 write_str_in_full(lock->lock_fd, "\n") != 1 ||
+			 write_str_in_full(lock->lk->fd, "\n") != 1 ||
 			 close_ref(lock) < 0)) {
 			status |= error("couldn't write %s",
 					lock->lk->filename.buf);
diff --git a/refs.h b/refs.h
index cf642e6ddc..6d7d9b40f3 100644
--- a/refs.h
+++ b/refs.h
@@ -191,7 +191,7 @@ extern int peel_ref(const char *refname, unsigned char *sha1);
 /*
  * Setup reflog before using. Set errno to something meaningful on failure.
  */
-int log_ref_setup(const char *refname, char *logfile, int bufsize);
+int log_ref_setup(const char *refname, struct strbuf *logfile);
 
 /** Reads log for the value of ref during at_time. **/
 extern int read_ref_at(const char *refname, unsigned int flags,
diff --git a/rerere.c b/rerere.c
index 31644dec04..94aea9a36f 100644
--- a/rerere.c
+++ b/rerere.c
@@ -659,6 +659,8 @@ int rerere_forget(struct pathspec *pathspec)
 		return error("Could not read index");
 
 	fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
+	if (fd < 0)
+		return 0;
 
 	unmerge_cache(pathspec);
 	find_conflict(&conflict);
diff --git a/revision.c b/revision.c
index 6399a0412c..7ddbaa083e 100644
--- a/revision.c
+++ b/revision.c
@@ -345,14 +345,24 @@ static struct commit *handle_commit(struct rev_info *revs,
 	die("%s is unknown object", name);
 }
 
-static int everybody_uninteresting(struct commit_list *orig)
+static int everybody_uninteresting(struct commit_list *orig,
+				   struct commit **interesting_cache)
 {
 	struct commit_list *list = orig;
+
+	if (*interesting_cache) {
+		struct commit *commit = *interesting_cache;
+		if (!(commit->object.flags & UNINTERESTING))
+			return 0;
+	}
+
 	while (list) {
 		struct commit *commit = list->item;
 		list = list->next;
 		if (commit->object.flags & UNINTERESTING)
 			continue;
+		if (interesting_cache)
+			*interesting_cache = commit;
 		return 0;
 	}
 	return 1;
@@ -940,7 +950,8 @@ static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 /* How many extra uninteresting commits we want to see.. */
 #define SLOP 5
 
-static int still_interesting(struct commit_list *src, unsigned long date, int slop)
+static int still_interesting(struct commit_list *src, unsigned long date, int slop,
+			     struct commit **interesting_cache)
 {
 	/*
 	 * No source list at all? We're definitely done..
@@ -959,7 +970,7 @@ static int still_interesting(struct commit_list *src, unsigned long date, int sl
 	 * Does the source list still have interesting commits in
 	 * it? Definitely not done..
 	 */
-	if (!everybody_uninteresting(src))
+	if (!everybody_uninteresting(src, interesting_cache))
 		return SLOP;
 
 	/* Ok, we're closing in.. */
@@ -1078,6 +1089,7 @@ static int limit_list(struct rev_info *revs)
 	struct commit_list *newlist = NULL;
 	struct commit_list **p = &newlist;
 	struct commit_list *bottom = NULL;
+	struct commit *interesting_cache = NULL;
 
 	if (revs->ancestry_path) {
 		bottom = collect_bottom_commits(list);
@@ -1094,6 +1106,9 @@ static int limit_list(struct rev_info *revs)
 		list = list->next;
 		free(entry);
 
+		if (commit == interesting_cache)
+			interesting_cache = NULL;
+
 		if (revs->max_age != -1 && (commit->date < revs->max_age))
 			obj->flags |= UNINTERESTING;
 		if (add_parents_to_list(revs, commit, &list, NULL) < 0)
@@ -1102,7 +1117,7 @@ static int limit_list(struct rev_info *revs)
 			mark_parents_uninteresting(commit);
 			if (revs->show_all)
 				p = &commit_list_insert(commit, p)->next;
-			slop = still_interesting(list, date, slop);
+			slop = still_interesting(list, date, slop, &interesting_cache);
 			if (slop)
 				continue;
 			/* If showing all, add the whole pending list to the end */
diff --git a/run-command.c b/run-command.c
index aad03ab705..4d73e90fad 100644
--- a/run-command.c
+++ b/run-command.c
@@ -795,9 +795,9 @@ int finish_async(struct async *async)
 #endif
 }
 
-char *find_hook(const char *name)
+const char *find_hook(const char *name)
 {
-	char *path = git_path("hooks/%s", name);
+	const char *path = git_path("hooks/%s", name);
 	if (access(path, X_OK) < 0)
 		path = NULL;
 
diff --git a/run-command.h b/run-command.h
index 263b9662ad..1103805af1 100644
--- a/run-command.h
+++ b/run-command.h
@@ -52,7 +52,7 @@ int start_command(struct child_process *);
 int finish_command(struct child_process *);
 int run_command(struct child_process *);
 
-extern char *find_hook(const char *name);
+extern const char *find_hook(const char *name);
 LAST_ARG_MUST_BE_NULL
 extern int run_hook_le(const char *const *env, const char *name, ...);
 extern int run_hook_ve(const char *const *env, const char *name, va_list args);
diff --git a/send-pack.c b/send-pack.c
index 2e07ac3339..2a64fec949 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -182,7 +182,7 @@ static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *c
 {
 	struct strbuf *sb = cb;
 	if (graft->nr_parent == -1)
-		packet_buf_write(sb, "shallow %s\n", sha1_to_hex(graft->sha1));
+		packet_buf_write(sb, "shallow %s\n", oid_to_hex(&graft->oid));
 	return 0;
 }
 
diff --git a/setup.c b/setup.c
index 979b13f0c6..863ddfd938 100644
--- a/setup.c
+++ b/setup.c
@@ -140,7 +140,9 @@ int check_filename(const char *prefix, const char *arg)
 		if (arg[2] == '\0') /* ":/" is root dir, always exists */
 			return 1;
 		name = arg + 2;
-	} else if (prefix)
+	} else if (!no_wildcard(arg))
+		return 1;
+	else if (prefix)
 		name = prefix_filename(prefix, strlen(prefix), arg);
 	else
 		name = arg;
@@ -224,6 +226,36 @@ void verify_non_filename(const char *prefix, const char *arg)
 	    "'git <command> [<revision>...] -- [<file>...]'", arg);
 }
 
+int get_common_dir(struct strbuf *sb, const char *gitdir)
+{
+	struct strbuf data = STRBUF_INIT;
+	struct strbuf path = STRBUF_INIT;
+	const char *git_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
+	int ret = 0;
+	if (git_common_dir) {
+		strbuf_addstr(sb, git_common_dir);
+		return 1;
+	}
+	strbuf_addf(&path, "%s/commondir", gitdir);
+	if (file_exists(path.buf)) {
+		if (strbuf_read_file(&data, path.buf, 0) <= 0)
+			die_errno(_("failed to read %s"), path.buf);
+		while (data.len && (data.buf[data.len - 1] == '\n' ||
+				    data.buf[data.len - 1] == '\r'))
+			data.len--;
+		data.buf[data.len] = '\0';
+		strbuf_reset(&path);
+		if (!is_absolute_path(data.buf))
+			strbuf_addf(&path, "%s/", gitdir);
+		strbuf_addbuf(&path, &data);
+		strbuf_addstr(sb, real_path(path.buf));
+		ret = 1;
+	} else
+		strbuf_addstr(sb, gitdir);
+	strbuf_release(&data);
+	strbuf_release(&path);
+	return ret;
+}
 
 /*
  * Test if it looks like we're at a git directory.
@@ -238,31 +270,40 @@ void verify_non_filename(const char *prefix, const char *arg)
  */
 int is_git_directory(const char *suspect)
 {
-	char path[PATH_MAX];
-	size_t len = strlen(suspect);
+	struct strbuf path = STRBUF_INIT;
+	int ret = 0;
+	size_t len;
+
+	/* Check worktree-related signatures */
+	strbuf_addf(&path, "%s/HEAD", suspect);
+	if (validate_headref(path.buf))
+		goto done;
 
-	if (PATH_MAX <= len + strlen("/objects"))
-		die("Too long path: %.*s", 60, suspect);
-	strcpy(path, suspect);
+	strbuf_reset(&path);
+	get_common_dir(&path, suspect);
+	len = path.len;
+
+	/* Check non-worktree-related signatures */
 	if (getenv(DB_ENVIRONMENT)) {
 		if (access(getenv(DB_ENVIRONMENT), X_OK))
-			return 0;
+			goto done;
 	}
 	else {
-		strcpy(path + len, "/objects");
-		if (access(path, X_OK))
-			return 0;
+		strbuf_setlen(&path, len);
+		strbuf_addstr(&path, "/objects");
+		if (access(path.buf, X_OK))
+			goto done;
 	}
 
-	strcpy(path + len, "/refs");
-	if (access(path, X_OK))
-		return 0;
+	strbuf_setlen(&path, len);
+	strbuf_addstr(&path, "/refs");
+	if (access(path.buf, X_OK))
+		goto done;
 
-	strcpy(path + len, "/HEAD");
-	if (validate_headref(path))
-		return 0;
-
-	return 1;
+	ret = 1;
+done:
+	strbuf_release(&path);
+	return ret;
 }
 
 int is_inside_git_dir(void)
@@ -304,9 +345,28 @@ void setup_work_tree(void)
 	initialized = 1;
 }
 
+static int check_repo_format(const char *var, const char *value, void *cb)
+{
+	if (strcmp(var, "core.repositoryformatversion") == 0)
+		repository_format_version = git_config_int(var, value);
+	else if (strcmp(var, "core.sharedrepository") == 0)
+		shared_repository = git_config_perm(var, value);
+	return 0;
+}
+
 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 {
-	char repo_config[PATH_MAX+1];
+	struct strbuf sb = STRBUF_INIT;
+	const char *repo_config;
+	config_fn_t fn;
+	int ret = 0;
+
+	if (get_common_dir(&sb, gitdir))
+		fn = check_repo_format;
+	else
+		fn = check_repository_format_version;
+	strbuf_addstr(&sb, "/config");
+	repo_config = sb.buf;
 
 	/*
 	 * git_config() can't be used here because it calls git_pathdup()
@@ -317,8 +377,7 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 	 * Use a gentler version of git_config() to check if this repo
 	 * is a good one.
 	 */
-	snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
-	git_config_early(check_repository_format_version, NULL, repo_config);
+	git_config_early(fn, NULL, repo_config);
 	if (GIT_REPO_VERSION < repository_format_version) {
 		if (!nongit_ok)
 			die ("Expected git repo version <= %d, found %d",
@@ -327,9 +386,21 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 			GIT_REPO_VERSION, repository_format_version);
 		warning("Please upgrade Git");
 		*nongit_ok = -1;
-		return -1;
+		ret = -1;
 	}
-	return 0;
+	strbuf_release(&sb);
+	return ret;
+}
+
+static void update_linked_gitdir(const char *gitfile, const char *gitdir)
+{
+	struct strbuf path = STRBUF_INIT;
+	struct stat st;
+
+	strbuf_addf(&path, "%s/gitfile", gitdir);
+	if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
+		write_file(path.buf, 0, "%s\n", gitfile);
+	strbuf_release(&path);
 }
 
 /*
@@ -380,6 +451,8 @@ const char *read_gitfile(const char *path)
 
 	if (!is_git_directory(dir))
 		die("Not a git repository: %s", dir);
+
+	update_linked_gitdir(path, dir);
 	path = real_path(dir);
 
 	free(buf);
@@ -799,11 +872,10 @@ int git_config_perm(const char *var, const char *value)
 
 int check_repository_format_version(const char *var, const char *value, void *cb)
 {
-	if (strcmp(var, "core.repositoryformatversion") == 0)
-		repository_format_version = git_config_int(var, value);
-	else if (strcmp(var, "core.sharedrepository") == 0)
-		shared_repository = git_config_perm(var, value);
-	else if (strcmp(var, "core.bare") == 0) {
+	int ret = check_repo_format(var, value, cb);
+	if (ret)
+		return ret;
+	if (strcmp(var, "core.bare") == 0) {
 		is_bare_repository_cfg = git_config_bool(var, value);
 		if (is_bare_repository_cfg == 1)
 			inside_work_tree = -1;
diff --git a/sha1_file.c b/sha1_file.c
index 88f06bac92..7e38148fe5 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -405,7 +405,7 @@ void add_to_alternates_file(const char *reference)
 {
 	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 	int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
-	char *alt = mkpath("%s\n", reference);
+	const char *alt = mkpath("%s\n", reference);
 	write_or_die(fd, alt, strlen(alt));
 	if (commit_lock_file(lock))
 		die("could not close alternates file");
@@ -1564,6 +1564,40 @@ int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long ma
 	return git_inflate(stream, 0);
 }
 
+static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
+					unsigned long mapsize, void *buffer,
+					unsigned long bufsiz, struct strbuf *header)
+{
+	int status;
+
+	status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
+
+	/*
+	 * Check if entire header is unpacked in the first iteration.
+	 */
+	if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+		return 0;
+
+	/*
+	 * buffer[0..bufsiz] was not large enough.  Copy the partial
+	 * result out to header, and then append the result of further
+	 * reading the stream.
+	 */
+	strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+	stream->next_out = buffer;
+	stream->avail_out = bufsiz;
+
+	do {
+		status = git_inflate(stream, 0);
+		strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+		if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+			return 0;
+		stream->next_out = buffer;
+		stream->avail_out = bufsiz;
+	} while (status != Z_STREAM_END);
+	return -1;
+}
+
 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
 {
 	int bytes = strlen(buffer) + 1;
@@ -1614,27 +1648,38 @@ static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long s
  * too permissive for what we want to check. So do an anal
  * object header parse by hand.
  */
-int parse_sha1_header(const char *hdr, unsigned long *sizep)
+static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
+			       unsigned int flags)
 {
-	char type[10];
-	int i;
+	const char *type_buf = hdr;
 	unsigned long size;
+	int type, type_len = 0;
 
 	/*
-	 * The type can be at most ten bytes (including the
-	 * terminating '\0' that we add), and is followed by
+	 * The type can be of any size but is followed by
 	 * a space.
 	 */
-	i = 0;
 	for (;;) {
 		char c = *hdr++;
 		if (c == ' ')
 			break;
-		type[i++] = c;
-		if (i >= sizeof(type))
-			return -1;
+		type_len++;
 	}
-	type[i] = 0;
+
+	type = type_from_string_gently(type_buf, type_len, 1);
+	if (oi->typename)
+		strbuf_add(oi->typename, type_buf, type_len);
+	/*
+	 * Set type to 0 if its an unknown object and
+	 * we're obtaining the type using '--allow-unkown-type'
+	 * option.
+	 */
+	if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
+		type = 0;
+	else if (type < 0)
+		die("invalid object type");
+	if (oi->typep)
+		*oi->typep = type;
 
 	/*
 	 * The length must follow immediately, and be in canonical
@@ -1652,12 +1697,24 @@ int parse_sha1_header(const char *hdr, unsigned long *sizep)
 			size = size * 10 + c;
 		}
 	}
-	*sizep = size;
+
+	if (oi->sizep)
+		*oi->sizep = size;
 
 	/*
 	 * The length must be followed by a zero byte
 	 */
-	return *hdr ? -1 : type_from_string(type);
+	return *hdr ? -1 : type;
+}
+
+int parse_sha1_header(const char *hdr, unsigned long *sizep)
+{
+	struct object_info oi;
+
+	oi.sizep = sizep;
+	oi.typename = NULL;
+	oi.typep = NULL;
+	return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
 }
 
 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
@@ -2473,10 +2530,8 @@ static int fill_pack_entry(const unsigned char *sha1,
 	 * answer, as it may have been deleted since the index was
 	 * loaded!
 	 */
-	if (!is_pack_valid(p)) {
-		warning("packfile %s cannot be accessed", p->pack_name);
+	if (!is_pack_valid(p))
 		return 0;
-	}
 	e->offset = offset;
 	e->p = p;
 	hashcpy(e->sha1, sha1);
@@ -2524,13 +2579,15 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
 }
 
 static int sha1_loose_object_info(const unsigned char *sha1,
-				  struct object_info *oi)
+				  struct object_info *oi,
+				  int flags)
 {
-	int status;
-	unsigned long mapsize, size;
+	int status = 0;
+	unsigned long mapsize;
 	void *map;
 	git_zstream stream;
 	char hdr[32];
+	struct strbuf hdrbuf = STRBUF_INIT;
 
 	if (oi->delta_base_sha1)
 		hashclr(oi->delta_base_sha1);
@@ -2543,7 +2600,7 @@ static int sha1_loose_object_info(const unsigned char *sha1,
 	 * return value implicitly indicates whether the
 	 * object even exists.
 	 */
-	if (!oi->typep && !oi->sizep) {
+	if (!oi->typep && !oi->typename && !oi->sizep) {
 		struct stat st;
 		if (stat_sha1_file(sha1, &st) < 0)
 			return -1;
@@ -2557,17 +2614,26 @@ static int sha1_loose_object_info(const unsigned char *sha1,
 		return -1;
 	if (oi->disk_sizep)
 		*oi->disk_sizep = mapsize;
-	if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+	if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
+		if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+			status = error("unable to unpack %s header with --allow-unknown-type",
+				       sha1_to_hex(sha1));
+	} else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
 		status = error("unable to unpack %s header",
 			       sha1_to_hex(sha1));
-	else if ((status = parse_sha1_header(hdr, &size)) < 0)
+	if (status < 0)
+		; /* Do nothing */
+	else if (hdrbuf.len) {
+		if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
+			status = error("unable to parse %s header with --allow-unknown-type",
+				       sha1_to_hex(sha1));
+	} else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
 		status = error("unable to parse %s header", sha1_to_hex(sha1));
-	else if (oi->sizep)
-		*oi->sizep = size;
 	git_inflate_end(&stream);
 	munmap(map, mapsize);
-	if (oi->typep)
+	if (status && oi->typep)
 		*oi->typep = status;
+	strbuf_release(&hdrbuf);
 	return 0;
 }
 
@@ -2576,6 +2642,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 	struct cached_object *co;
 	struct pack_entry e;
 	int rtype;
+	enum object_type real_type;
 	const unsigned char *real = lookup_replace_object_extended(sha1, flags);
 
 	co = find_cached_object(real);
@@ -2588,13 +2655,15 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 			*(oi->disk_sizep) = 0;
 		if (oi->delta_base_sha1)
 			hashclr(oi->delta_base_sha1);
+		if (oi->typename)
+			strbuf_addstr(oi->typename, typename(co->type));
 		oi->whence = OI_CACHED;
 		return 0;
 	}
 
 	if (!find_pack_entry(real, &e)) {
 		/* Most likely it's a loose object. */
-		if (!sha1_loose_object_info(real, oi)) {
+		if (!sha1_loose_object_info(real, oi, flags)) {
 			oi->whence = OI_LOOSE;
 			return 0;
 		}
@@ -2605,9 +2674,18 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 			return -1;
 	}
 
+	/*
+	 * packed_object_info() does not follow the delta chain to
+	 * find out the real type, unless it is given oi->typep.
+	 */
+	if (oi->typename && !oi->typep)
+		oi->typep = &real_type;
+
 	rtype = packed_object_info(e.p, e.offset, oi);
 	if (rtype < 0) {
 		mark_bad_packed_object(e.p, real);
+		if (oi->typep == &real_type)
+			oi->typep = NULL;
 		return sha1_object_info_extended(real, oi, 0);
 	} else if (in_delta_base_cache(e.p, e.offset)) {
 		oi->whence = OI_DBCACHED;
@@ -2618,6 +2696,10 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 		oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
 					 rtype == OBJ_OFS_DELTA);
 	}
+	if (oi->typename)
+		strbuf_addstr(oi->typename, typename(*oi->typep));
+	if (oi->typep == &real_type)
+		oi->typep = NULL;
 
 	return 0;
 }
@@ -2999,12 +3081,18 @@ static int freshen_loose_object(const unsigned char *sha1)
 static int freshen_packed_object(const unsigned char *sha1)
 {
 	struct pack_entry e;
-	return find_pack_entry(sha1, &e) && freshen_file(e.p->pack_name);
+	if (!find_pack_entry(sha1, &e))
+		return 0;
+	if (e.p->freshened)
+		return 1;
+	if (!freshen_file(e.p->pack_name))
+		return 0;
+	e.p->freshened = 1;
+	return 1;
 }
 
-int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
 {
-	unsigned char sha1[20];
 	char hdr[32];
 	int hdrlen;
 
@@ -3012,13 +3100,32 @@ int write_sha1_file(const void *buf, unsigned long len, const char *type, unsign
 	 * it out into .git/objects/??/?{38} file.
 	 */
 	write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
-	if (returnsha1)
-		hashcpy(returnsha1, sha1);
-	if (freshen_loose_object(sha1) || freshen_packed_object(sha1))
+	if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
 		return 0;
 	return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
 
+int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
+			     unsigned char *sha1, unsigned flags)
+{
+	char *header;
+	int hdrlen, status = 0;
+
+	/* type string, SP, %lu of the length plus NUL must fit this */
+	header = xmalloc(strlen(type) + 32);
+	write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
+
+	if (!(flags & HASH_WRITE_OBJECT))
+		goto cleanup;
+	if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+		goto cleanup;
+	status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
+
+cleanup:
+	free(header);
+	return status;
+}
+
 int force_object_loose(const unsigned char *sha1, time_t mtime)
 {
 	void *buf;
@@ -3179,7 +3286,7 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
 	int ret;
 
 	if (!size) {
-		ret = index_mem(sha1, NULL, size, type, path, flags);
+		ret = index_mem(sha1, "", size, type, path, flags);
 	} else if (size <= SMALL_FILE_SIZE) {
 		char *buf = xmalloc(size);
 		if (size == read_in_full(fd, buf, size))
@@ -3418,7 +3525,7 @@ static int loose_from_alt_odb(struct alternate_object_database *alt,
 	return r;
 }
 
-int for_each_loose_object(each_loose_object_fn cb, void *data)
+int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
 {
 	struct loose_alt_odb_data alt;
 	int r;
@@ -3428,6 +3535,9 @@ int for_each_loose_object(each_loose_object_fn cb, void *data)
 	if (r)
 		return r;
 
+	if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
+		return 0;
+
 	alt.cb = cb;
 	alt.data = data;
 	return foreach_alt_odb(loose_from_alt_odb, &alt);
@@ -3452,13 +3562,15 @@ static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn c
 	return r;
 }
 
-int for_each_packed_object(each_packed_object_fn cb, void *data)
+int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 {
 	struct packed_git *p;
 	int r = 0;
 
 	prepare_packed_git();
 	for (p = packed_git; p; p = p->next) {
+		if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
+			continue;
 		r = for_each_object_in_pack(p, cb, data);
 		if (r)
 			break;
diff --git a/sha1_name.c b/sha1_name.c
index 6d10f052b5..46218ba02c 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -6,6 +6,7 @@
 #include "tree-walk.h"
 #include "refs.h"
 #include "remote.h"
+#include "dir.h"
 
 static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
 
@@ -1237,14 +1238,13 @@ static void diagnose_invalid_sha1_path(const char *prefix,
 				       const char *object_name,
 				       int object_name_len)
 {
-	struct stat st;
 	unsigned char sha1[20];
 	unsigned mode;
 
 	if (!prefix)
 		prefix = "";
 
-	if (!lstat(filename, &st))
+	if (file_exists(filename))
 		die("Path '%s' exists on disk, but not in '%.*s'.",
 		    filename, object_name_len, object_name);
 	if (errno == ENOENT || errno == ENOTDIR) {
@@ -1271,7 +1271,6 @@ static void diagnose_invalid_index_path(int stage,
 					const char *prefix,
 					const char *filename)
 {
-	struct stat st;
 	const struct cache_entry *ce;
 	int pos;
 	unsigned namelen = strlen(filename);
@@ -1314,7 +1313,7 @@ static void diagnose_invalid_index_path(int stage,
 			    ce_stage(ce), filename);
 	}
 
-	if (!lstat(filename, &st))
+	if (file_exists(filename))
 		die("Path '%s' exists on disk, but not in the index.", filename);
 	if (errno == ENOENT || errno == ENOTDIR)
 		die("Path '%s' does not exist (neither on disk nor in the index).",
@@ -1434,11 +1433,19 @@ static int get_sha1_with_context_1(const char *name,
 			new_filename = resolve_relative_path(filename);
 			if (new_filename)
 				filename = new_filename;
-			ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
-			if (ret && only_to_die) {
-				diagnose_invalid_sha1_path(prefix, filename,
-							   tree_sha1,
-							   name, len);
+			if (flags & GET_SHA1_FOLLOW_SYMLINKS) {
+				ret = get_tree_entry_follow_symlinks(tree_sha1,
+					filename, sha1, &oc->symlink_path,
+					&oc->mode);
+			} else {
+				ret = get_tree_entry(tree_sha1, filename,
+						     sha1, &oc->mode);
+				if (ret && only_to_die) {
+					diagnose_invalid_sha1_path(prefix,
+								   filename,
+								   tree_sha1,
+								   name, len);
+				}
 			}
 			hashcpy(oc->tree, tree_sha1);
 			strlcpy(oc->path, filename, sizeof(oc->path));
@@ -1469,5 +1476,7 @@ void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
 
 int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
 {
+	if (flags & GET_SHA1_FOLLOW_SYMLINKS && flags & GET_SHA1_ONLY_TO_DIE)
+		die("BUG: incompatible flags for get_sha1_with_context");
 	return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
 }
diff --git a/shallow.c b/shallow.c
index d8bf40ad4b..d08d264dd2 100644
--- a/shallow.c
+++ b/shallow.c
@@ -31,7 +31,7 @@ int register_shallow(const unsigned char *sha1)
 		xmalloc(sizeof(struct commit_graft));
 	struct commit *commit = lookup_commit(sha1);
 
-	hashcpy(graft->sha1, sha1);
+	hashcpy(graft->oid.hash, sha1);
 	graft->nr_parent = -1;
 	if (commit && commit->object.parsed)
 		commit->parents = NULL;
@@ -159,11 +159,11 @@ struct write_shallow_data {
 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 {
 	struct write_shallow_data *data = cb_data;
-	const char *hex = sha1_to_hex(graft->sha1);
+	const char *hex = oid_to_hex(&graft->oid);
 	if (graft->nr_parent != -1)
 		return 0;
 	if (data->flags & SEEN_ONLY) {
-		struct commit *c = lookup_commit(graft->sha1);
+		struct commit *c = lookup_commit(graft->oid.hash);
 		if (!c || !(c->object.flags & SEEN)) {
 			if (data->flags & VERBOSE)
 				printf("Removing %s from .git/shallow\n",
@@ -282,7 +282,7 @@ static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *c
 {
 	int fd = *(int *)cb;
 	if (graft->nr_parent == -1)
-		packet_write(fd, "shallow %s\n", sha1_to_hex(graft->sha1));
+		packet_write(fd, "shallow %s\n", oid_to_hex(&graft->oid));
 	return 0;
 }
 
diff --git a/split-index.c b/split-index.c
index 21485e2066..968b780a06 100644
--- a/split-index.c
+++ b/split-index.c
@@ -41,13 +41,6 @@ int read_link_extension(struct index_state *istate,
 	return 0;
 }
 
-static int write_strbuf(void *user_data, const void *data, size_t len)
-{
-	struct strbuf *sb = user_data;
-	strbuf_add(sb, data, len);
-	return len;
-}
-
 int write_link_extension(struct strbuf *sb,
 			 struct index_state *istate)
 {
@@ -55,8 +48,8 @@ int write_link_extension(struct strbuf *sb,
 	strbuf_add(sb, si->base_sha1, 20);
 	if (!si->delete_bitmap && !si->replace_bitmap)
 		return 0;
-	ewah_serialize_to(si->delete_bitmap, write_strbuf, sb);
-	ewah_serialize_to(si->replace_bitmap, write_strbuf, sb);
+	ewah_serialize_strbuf(si->delete_bitmap, sb);
+	ewah_serialize_strbuf(si->replace_bitmap, sb);
 	return 0;
 }
 
diff --git a/strbuf.c b/strbuf.c
index 88cafd4a70..0d4f4e54ec 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -435,6 +435,47 @@ int strbuf_getcwd(struct strbuf *sb)
 	return -1;
 }
 
+#ifdef HAVE_GETDELIM
+int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
+{
+	ssize_t r;
+
+	if (feof(fp))
+		return EOF;
+
+	strbuf_reset(sb);
+
+	/* Translate slopbuf to NULL, as we cannot call realloc on it */
+	if (!sb->alloc)
+		sb->buf = NULL;
+	r = getdelim(&sb->buf, &sb->alloc, term, fp);
+
+	if (r > 0) {
+		sb->len = r;
+		return 0;
+	}
+	assert(r == -1);
+
+	/*
+	 * Normally we would have called xrealloc, which will try to free
+	 * memory and recover. But we have no way to tell getdelim() to do so.
+	 * Worse, we cannot try to recover ENOMEM ourselves, because we have
+	 * no idea how many bytes were read by getdelim.
+	 *
+	 * Dying here is reasonable. It mirrors what xrealloc would do on
+	 * catastrophic memory failure. We skip the opportunity to free pack
+	 * memory and retry, but that's unlikely to help for a malloc small
+	 * enough to hold a single line of input, anyway.
+	 */
+	if (errno == ENOMEM)
+		die("Out of memory, getdelim failed");
+
+	/* Restore slopbuf that we moved out of the way before */
+	if (!sb->buf)
+		strbuf_init(sb, 0);
+	return EOF;
+}
+#else
 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 {
 	int ch;
@@ -443,18 +484,22 @@ int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 		return EOF;
 
 	strbuf_reset(sb);
-	while ((ch = fgetc(fp)) != EOF) {
-		strbuf_grow(sb, 1);
+	flockfile(fp);
+	while ((ch = getc_unlocked(fp)) != EOF) {
+		if (!strbuf_avail(sb))
+			strbuf_grow(sb, 1);
 		sb->buf[sb->len++] = ch;
 		if (ch == term)
 			break;
 	}
+	funlockfile(fp);
 	if (ch == EOF && sb->len == 0)
 		return EOF;
 
 	sb->buf[sb->len] = '\0';
 	return 0;
 }
+#endif
 
 int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
 {
diff --git a/strbuf.h b/strbuf.h
index 1883494ca3..01c5c6371b 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -205,7 +205,8 @@ extern int strbuf_cmp(const struct strbuf *, const struct strbuf *);
  */
 static inline void strbuf_addch(struct strbuf *sb, int c)
 {
-	strbuf_grow(sb, 1);
+	if (!strbuf_avail(sb))
+		strbuf_grow(sb, 1);
 	sb->buf[sb->len++] = c;
 	sb->buf[sb->len] = '\0';
 }
diff --git a/submodule.c b/submodule.c
index c0e6c81fc4..b8747f5c26 100644
--- a/submodule.c
+++ b/submodule.c
@@ -891,7 +891,6 @@ int submodule_uses_gitfile(const char *path)
 
 int ok_to_remove_submodule(const char *path)
 {
-	struct stat st;
 	ssize_t len;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	const char *argv[] = {
@@ -904,7 +903,7 @@ int ok_to_remove_submodule(const char *path)
 	struct strbuf buf = STRBUF_INIT;
 	int ok_to_remove = 1;
 
-	if ((lstat(path, &st) < 0) || is_empty_dir(path))
+	if (!file_exists(path) || is_empty_dir(path))
 		return 1;
 
 	if (!submodule_uses_gitfile(path))
@@ -1100,16 +1099,11 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
 	struct strbuf file_name = STRBUF_INIT;
 	struct strbuf rel_path = STRBUF_INIT;
 	const char *real_work_tree = xstrdup(real_path(work_tree));
-	FILE *fp;
 
 	/* Update gitfile */
 	strbuf_addf(&file_name, "%s/.git", work_tree);
-	fp = fopen(file_name.buf, "w");
-	if (!fp)
-		die(_("Could not create git link %s"), file_name.buf);
-	fprintf(fp, "gitdir: %s\n", relative_path(git_dir, real_work_tree,
-						  &rel_path));
-	fclose(fp);
+	write_file(file_name.buf, 1, "gitdir: %s\n",
+		   relative_path(git_dir, real_work_tree, &rel_path));
 
 	/* Update core.worktree setting */
 	strbuf_reset(&file_name);
diff --git a/t/lib-git-p4.sh b/t/lib-git-p4.sh
index 5aa8adcf9c..75482254a3 100644
--- a/t/lib-git-p4.sh
+++ b/t/lib-git-p4.sh
@@ -69,7 +69,7 @@ start_p4d() {
 	(
 		cd "$db" &&
 		{
-			p4d -q -p $P4DPORT &
+			p4d -q -p $P4DPORT "$@" &
 			echo $! >"$pidfile"
 		}
 	) &&
diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index e6adf2f82d..e9714467d0 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -30,6 +30,18 @@
 # Copyright (c) 2008 Clemens Buchacher <drizzd@aon.at>
 #
 
+if test -n "$NO_CURL"
+then
+	skip_all='skipping test, git built without http support'
+	test_done
+fi
+
+if test -n "$NO_EXPAT" && test -n "$LIB_HTTPD_DAV"
+then
+	skip_all='skipping test, git built without expat support'
+	test_done
+fi
+
 test_tristate GIT_TEST_HTTPD
 if test "$GIT_TEST_HTTPD" = false
 then
diff --git a/t/t0008-ignores.sh b/t/t0008-ignores.sh
index 8dc6939b90..4ef5ed484c 100755
--- a/t/t0008-ignores.sh
+++ b/t/t0008-ignores.sh
@@ -831,4 +831,14 @@ test_expect_success !MINGW,!CYGWIN 'correct handling of backslashes' '
 	test_cmp err.expect err
 '
 
+test_expect_success 'info/exclude trumps core.excludesfile' '
+	echo >>global-excludes usually-ignored &&
+	echo >>.git/info/exclude "!usually-ignored" &&
+	>usually-ignored &&
+	echo "?? usually-ignored" >expect &&
+
+	git status --porcelain usually-ignored >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index ca7d2a630a..718efa04d3 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -204,6 +204,16 @@ test_expect_success 'filtering large input to small output should use little mem
 	GIT_MMAP_LIMIT=1m GIT_ALLOC_LIMIT=1m git add 30MB
 '
 
+test_expect_success 'filter that does not read is fine' '
+	test-genrandom foo $((128 * 1024 + 1)) >big &&
+	echo "big filter=epipe" >.gitattributes &&
+	git config filter.epipe.clean "echo xyzzy" &&
+	git add big &&
+	git cat-file blob :big >actual &&
+	echo xyzzy >expect &&
+	test_cmp expect actual
+'
+
 test_expect_success EXPENSIVE 'filter large file' '
 	git config filter.largefile.smudge cat &&
 	git config filter.largefile.clean cat &&
@@ -216,4 +226,30 @@ test_expect_success EXPENSIVE 'filter large file' '
 	! test -s err
 '
 
+test_expect_success "filter: clean empty file" '
+	git config filter.in-repo-header.clean  "echo cleaned && cat" &&
+	git config filter.in-repo-header.smudge "sed 1d" &&
+
+	echo "empty-in-worktree    filter=in-repo-header" >>.gitattributes &&
+	>empty-in-worktree &&
+
+	echo cleaned >expected &&
+	git add empty-in-worktree &&
+	git show :empty-in-worktree >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success "filter: smudge empty file" '
+	git config filter.empty-in-repo.clean "cat >/dev/null" &&
+	git config filter.empty-in-repo.smudge "echo smudged && cat" &&
+
+	echo "empty-in-repo filter=empty-in-repo" >>.gitattributes &&
+	echo dead data walking >empty-in-repo &&
+	git add empty-in-repo &&
+
+	echo smudged >expected &&
+	git checkout-index --prefix=filtered- empty-in-repo &&
+	test_cmp expected filtered-empty-in-repo
+'
+
 test_done
diff --git a/t/t0027-auto-crlf.sh b/t/t0027-auto-crlf.sh
index 452320df83..1a56e5e82e 100755
--- a/t/t0027-auto-crlf.sh
+++ b/t/t0027-auto-crlf.sh
@@ -57,28 +57,35 @@ create_gitattributes () {
 
 check_warning () {
 	case "$1" in
-	LF_CRLF) grep "LF will be replaced by CRLF" $2;;
-	CRLF_LF) grep "CRLF will be replaced by LF" $2;;
-	'')
-		>expect
-		grep "will be replaced by" $2 >actual
-		test_cmp expect actual
-		;;
-	*) false ;;
+	LF_CRLF) echo "warning: LF will be replaced by CRLF" >"$2".expect ;;
+	CRLF_LF) echo "warning: CRLF will be replaced by LF" >"$2".expect ;;
+	'')	                                                 >"$2".expect ;;
+	*) echo >&2 "Illegal 1": "$1" ; return false ;;
 	esac
+	grep "will be replaced by" "$2" | sed -e "s/\(.*\) in [^ ]*$/\1/" >"$2".actual
+	test_cmp "$2".expect "$2".actual
 }
 
-create_file_in_repo () {
+commit_check_warn () {
 	crlf=$1
 	attr=$2
 	lfname=$3
 	crlfname=$4
-	lfmixcrlf=$5
-	lfmixcr=$6
-	crlfnul=$7
-	create_gitattributes "$attr" &&
+	repoMIX=$5
+	lfmixcrlf=$6
+	lfmixcr=$7
+	crlfnul=$8
 	pfx=crlf_${crlf}_attr_${attr}
-	for f in LF CRLF LF_mix_CR CRLF_mix_LF CRLF_nul
+	# Special handling for repoMIX: It should already be in the repo
+	# with CRLF
+	f=repoMIX
+	fname=${pfx}_$f.txt
+	echo >.gitattributes &&
+	cp $f $fname &&
+	git -c core.autocrlf=false add $fname 2>"${pfx}_$f.err" &&
+	git commit -m "repoMIX" &&
+	create_gitattributes "$attr" &&
+	for f in LF CRLF repoMIX LF_mix_CR CRLF_mix_LF LF_nul CRLF_nul
 	do
 		fname=${pfx}_$f.txt &&
 		cp $f $fname &&
@@ -109,7 +116,7 @@ check_files_in_repo () {
 }
 
 
-check_files_in_ws () {
+checkout_files () {
 	eol=$1
 	crlf=$2
 	attr=$3
@@ -122,7 +129,7 @@ check_files_in_ws () {
 	git config core.autocrlf $crlf &&
 	pfx=eol_${eol}_crlf_${crlf}_attr_${attr}_ &&
 	src=crlf_false_attr__ &&
-	for f in LF CRLF LF_mix_CR CRLF_mix_LF CRLF_nul
+	for f in LF CRLF LF_mix_CR CRLF_mix_LF LF_nul
 	do
 		rm $src$f.txt &&
 		if test -z "$eol"; then
@@ -144,8 +151,8 @@ check_files_in_ws () {
 	test_expect_success "checkout core.eol=$eol core.autocrlf=$crlf gitattributes=$attr file=LF_mix_CR" "
 		compare_ws_file $pfx $lfmixcr   ${src}LF_mix_CR.txt
 	"
-	test_expect_success "checkout core.eol=$eol core.autocrlf=$crlf gitattributes=$attr file=CRLF_nul" "
-		compare_ws_file $pfx $crlfnul   ${src}CRLF_nul.txt
+	test_expect_success "checkout core.eol=$eol core.autocrlf=$crlf gitattributes=$attr file=LF_nul" "
+		compare_ws_file $pfx $crlfnul   ${src}LF_nul.txt
 	"
 }
 
@@ -157,6 +164,7 @@ test_expect_success 'setup master' '
 	git commit -m "add .gitattributes" "" &&
 	printf "line1\nline2\nline3"     >LF &&
 	printf "line1\r\nline2\r\nline3" >CRLF &&
+	printf "line1\r\nline2\nline3"   >repoMIX &&
 	printf "line1\r\nline2\nline3"   >CRLF_mix_LF &&
 	printf "line1\nline2\rline3"     >LF_mix_CR &&
 	printf "line1\r\nline2\rline3"   >CRLF_mix_CR &&
@@ -169,40 +177,55 @@ test_expect_success 'setup master' '
 warn_LF_CRLF="LF will be replaced by CRLF"
 warn_CRLF_LF="CRLF will be replaced by LF"
 
-test_expect_success 'add files empty attr' '
-	create_file_in_repo false ""     ""        ""        ""        ""        "" &&
-	create_file_in_repo true  ""     "LF_CRLF" ""        "LF_CRLF" ""        "" &&
-	create_file_in_repo input ""     ""        "CRLF_LF" "CRLF_LF" ""        ""
+# WILC stands for "Warn if (this OS) converts LF into CRLF".
+# WICL: Warn if CRLF becomes LF
+# WAMIX: Mixed line endings: either CRLF->LF or LF->CRLF
+if test_have_prereq NATIVE_CRLF
+then
+	WILC=LF_CRLF
+	WICL=
+	WAMIX=LF_CRLF
+else
+	WILC=
+	WICL=CRLF_LF
+	WAMIX=CRLF_LF
+fi
+
+#                         attr   LF        CRLF      repoMIX   CRLFmixLF LFmixCR   CRLFNUL
+test_expect_success 'commit files empty attr' '
+	commit_check_warn false ""     ""        ""        ""        ""        ""        "" &&
+	commit_check_warn true  ""     "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" ""        "" &&
+	commit_check_warn input ""     ""        "CRLF_LF" "CRLF_LF" "CRLF_LF" ""        ""
 '
 
-test_expect_success 'add files attr=auto' '
-	create_file_in_repo false "auto" ""        "CRLF_LF" "CRLF_LF" ""        "" &&
-	create_file_in_repo true  "auto" "LF_CRLF" ""        "LF_CRLF" ""        "" &&
-	create_file_in_repo input "auto" ""        "CRLF_LF" "CRLF_LF" ""        ""
+test_expect_success 'commit files attr=auto' '
+	commit_check_warn false "auto" "$WILC"   "$WICL"   "$WAMIX"  "$WAMIX"  ""        "" &&
+	commit_check_warn true  "auto" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" ""        "" &&
+	commit_check_warn input "auto" ""        "CRLF_LF" "CRLF_LF" "CRLF_LF" ""        ""
 '
 
-test_expect_success 'add files attr=text' '
-	create_file_in_repo false "text" ""        "CRLF_LF" "CRLF_LF" ""        "CRLF_LF" &&
-	create_file_in_repo true  "text" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" ""        &&
-	create_file_in_repo input "text" ""        "CRLF_LF" "CRLF_LF" ""        "CRLF_LF"
+test_expect_success 'commit files attr=text' '
+	commit_check_warn false "text" "$WILC"   "$WICL"   "$WAMIX"  "$WAMIX"  "$WILC"   "$WICL"   &&
+	commit_check_warn true  "text" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "LF_CRLF" ""        &&
+	commit_check_warn input "text" ""        "CRLF_LF" "CRLF_LF" "CRLF_LF" ""        "CRLF_LF"
 '
 
-test_expect_success 'add files attr=-text' '
-	create_file_in_repo false "-text" ""       ""        ""        ""        "" &&
-	create_file_in_repo true  "-text" ""       ""        ""        ""        "" &&
-	create_file_in_repo input "-text" ""       ""        ""        ""        ""
+test_expect_success 'commit files attr=-text' '
+	commit_check_warn false "-text" ""       ""        ""        ""        ""        "" &&
+	commit_check_warn true  "-text" ""       ""        ""        ""        ""        "" &&
+	commit_check_warn input "-text" ""       ""        ""        ""        ""        ""
 '
 
-test_expect_success 'add files attr=lf' '
-	create_file_in_repo false "lf"    ""       "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF" &&
-	create_file_in_repo true  "lf"    ""       "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF" &&
-	create_file_in_repo input "lf"    ""       "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF"
+test_expect_success 'commit files attr=lf' '
+	commit_check_warn false "lf"    ""       "CRLF_LF" "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF" &&
+	commit_check_warn true  "lf"    ""       "CRLF_LF" "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF" &&
+	commit_check_warn input "lf"    ""       "CRLF_LF" "CRLF_LF" "CRLF_LF"  ""       "CRLF_LF"
 '
 
-test_expect_success 'add files attr=crlf' '
-	create_file_in_repo false "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "" &&
-	create_file_in_repo true  "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "" &&
-	create_file_in_repo input "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" ""
+test_expect_success 'commit files attr=crlf' '
+	commit_check_warn false "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "LF_CRLF" "" &&
+	commit_check_warn true  "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "LF_CRLF" "" &&
+	commit_check_warn input "crlf" "LF_CRLF" ""        "LF_CRLF" "LF_CRLF" "LF_CRLF" ""
 '
 
 test_expect_success 'create files cleanup' '
@@ -237,7 +260,7 @@ test_expect_success 'commit -text' '
 ################################################################################
 # Check how files in the repo are changed when they are checked out
 # How to read the table below:
-# - check_files_in_ws will check multiple files with a combination of settings
+# - checkout_files will check multiple files with a combination of settings
 #   and attributes (core.autocrlf=input is forbidden with core.eol=crlf)
 # - parameter $1 : core.eol               lf | crlf
 # - parameter $2 : core.autocrlf          false | true | input
@@ -249,87 +272,89 @@ test_expect_success 'commit -text' '
 # - parameter $8 : reference for a file with CRLF and a NUL (should be handled as binary when auto)
 
 #                                            What we have in the repo:
-#                														 ----------------- EOL in repo ----------------
-#                														 LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
+#                                            ----------------- EOL in repo ----------------
+#                                            LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
 #                   settings with checkout:
 #                   core.   core.   .gitattr
 #                    eol     acrlf
 #                                            ----------------------------------------------
 #                                            What we want to have in the working tree:
-if test_have_prereq MINGW
+if test_have_prereq NATIVE_CRLF
 then
 MIX_CRLF_LF=CRLF
 MIX_LF_CR=CRLF_mix_CR
 NL=CRLF
+LFNUL=CRLF_nul
 else
 MIX_CRLF_LF=CRLF_mix_LF
 MIX_LF_CR=LF_mix_CR
 NL=LF
+LFNUL=LF_nul
 fi
 export CRLF_MIX_LF_CR MIX NL
 
-check_files_in_ws    lf      false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      input  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      false "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      input "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      false "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    lf      input "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      input "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      input "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    lf      false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    lf      true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    lf      input "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-
-check_files_in_ws    crlf    false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    false "auto"    CRLF  CRLF  CRLF         LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    false "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    crlf    true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    crlf    false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    crlf    false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    crlf    true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-
-check_files_in_ws    ""      false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      input  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      false "auto"    $NL   CRLF  $MIX_CRLF_LF LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      input "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      false "text"    $NL   CRLF  $MIX_CRLF_LF $MIX_LF_CR   CRLF_nul
-check_files_in_ws    ""      true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    ""      input "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      input "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      input "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    ""      false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    ""      true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    ""      input "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-
-check_files_in_ws    native  false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  false "auto"    $NL   CRLF  $MIX_CRLF_LF LF_mix_CR    CRLF_nul
-check_files_in_ws    native  true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    CRLF_nul
-check_files_in_ws    native  false "text"    $NL   CRLF  $MIX_CRLF_LF $MIX_LF_CR   CRLF_nul
-check_files_in_ws    native  true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    native  false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    CRLF_nul
-check_files_in_ws    native  false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
-check_files_in_ws    native  true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    lf      false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      input  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      false "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    LF_nul
+checkout_files    lf      input "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      false "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    lf      input "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      input "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      input "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    lf      false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    lf      true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    lf      input "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+
+checkout_files    crlf    false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    false "auto"    CRLF  CRLF  CRLF         LF_mix_CR    LF_nul
+checkout_files    crlf    true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    LF_nul
+checkout_files    crlf    false "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    crlf    true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    crlf    false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    crlf    false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    crlf    true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+
+checkout_files    ""      false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      input  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      false "auto"    $NL   CRLF  $MIX_CRLF_LF LF_mix_CR    LF_nul
+checkout_files    ""      true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    LF_nul
+checkout_files    ""      input "auto"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      false "text"    $NL   CRLF  $MIX_CRLF_LF $MIX_LF_CR   $LFNUL
+checkout_files    ""      true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    ""      input "text"    LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      input "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      input "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    ""      false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    ""      true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    ""      input "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+
+checkout_files    native  false  ""       LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  true   ""       CRLF  CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  false "auto"    $NL   CRLF  $MIX_CRLF_LF LF_mix_CR    LF_nul
+checkout_files    native  true  "auto"    CRLF  CRLF  CRLF         LF_mix_CR    LF_nul
+checkout_files    native  false "text"    $NL   CRLF  $MIX_CRLF_LF $MIX_LF_CR   $LFNUL
+checkout_files    native  true  "text"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    native  false "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  true  "-text"   LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  false "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  true  "lf"      LF    CRLF  CRLF_mix_LF  LF_mix_CR    LF_nul
+checkout_files    native  false "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
+checkout_files    native  true  "crlf"    CRLF  CRLF  CRLF         CRLF_mix_CR  CRLF_nul
 
 test_done
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index c0143a0a70..93605f42f2 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -19,6 +19,14 @@ relative_path() {
 	"test \"\$(test-path-utils relative_path '$1' '$2')\" = '$expected'"
 }
 
+test_git_path() {
+	test_expect_success "git-path $1 $2 => $3" "
+		$1 git rev-parse --git-path $2 >actual &&
+		echo $3 >expect &&
+		test_cmp expect actual
+	"
+}
+
 # On Windows, we are using MSYS's bash, which mangles the paths.
 # Absolute paths are anchored at the MSYS installation directory,
 # which means that the path / accounts for this many characters:
@@ -244,4 +252,32 @@ relative_path "<null>"		"<empty>"	./
 relative_path "<null>"		"<null>"	./
 relative_path "<null>"		/foo/a/b	./
 
+test_git_path A=B                info/grafts .git/info/grafts
+test_git_path GIT_GRAFT_FILE=foo info/grafts foo
+test_git_path GIT_GRAFT_FILE=foo info/////grafts foo
+test_git_path GIT_INDEX_FILE=foo index foo
+test_git_path GIT_INDEX_FILE=foo index/foo .git/index/foo
+test_git_path GIT_INDEX_FILE=foo index2 .git/index2
+test_expect_success 'setup fake objects directory foo' 'mkdir foo'
+test_git_path GIT_OBJECT_DIRECTORY=foo objects foo
+test_git_path GIT_OBJECT_DIRECTORY=foo objects/foo foo/foo
+test_git_path GIT_OBJECT_DIRECTORY=foo objects2 .git/objects2
+test_expect_success 'setup common repository' 'git --git-dir=bar init'
+test_git_path GIT_COMMON_DIR=bar index                    .git/index
+test_git_path GIT_COMMON_DIR=bar HEAD                     .git/HEAD
+test_git_path GIT_COMMON_DIR=bar logs/HEAD                .git/logs/HEAD
+test_git_path GIT_COMMON_DIR=bar objects                  bar/objects
+test_git_path GIT_COMMON_DIR=bar objects/bar              bar/objects/bar
+test_git_path GIT_COMMON_DIR=bar info/exclude             bar/info/exclude
+test_git_path GIT_COMMON_DIR=bar info/grafts              bar/info/grafts
+test_git_path GIT_COMMON_DIR=bar info/sparse-checkout     .git/info/sparse-checkout
+test_git_path GIT_COMMON_DIR=bar remotes/bar              bar/remotes/bar
+test_git_path GIT_COMMON_DIR=bar branches/bar             bar/branches/bar
+test_git_path GIT_COMMON_DIR=bar logs/refs/heads/master   bar/logs/refs/heads/master
+test_git_path GIT_COMMON_DIR=bar refs/heads/master        bar/refs/heads/master
+test_git_path GIT_COMMON_DIR=bar hooks/me                 bar/hooks/me
+test_git_path GIT_COMMON_DIR=bar config                   bar/config
+test_git_path GIT_COMMON_DIR=bar packed-refs              bar/packed-refs
+test_git_path GIT_COMMON_DIR=bar shallow                  bar/shallow
+
 test_done
diff --git a/t/t0302-credential-store.sh b/t/t0302-credential-store.sh
index f61b40c69b..0979df93a1 100755
--- a/t/t0302-credential-store.sh
+++ b/t/t0302-credential-store.sh
@@ -6,4 +6,118 @@ test_description='credential-store tests'
 
 helper_test store
 
+test_expect_success 'when xdg file does not exist, xdg file not created' '
+	test_path_is_missing "$HOME/.config/git/credentials" &&
+	test -s "$HOME/.git-credentials"
+'
+
+test_expect_success 'setup xdg file' '
+	rm -f "$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	>"$HOME/.config/git/credentials"
+'
+
+helper_test store
+
+test_expect_success 'when xdg file exists, home file not created' '
+	test -s "$HOME/.config/git/credentials" &&
+	test_path_is_missing "$HOME/.git-credentials"
+'
+
+test_expect_success 'setup custom xdg file' '
+	rm -f "$HOME/.git-credentials" &&
+	rm -f "$HOME/.config/git/credentials" &&
+	mkdir -p "$HOME/xdg/git" &&
+	>"$HOME/xdg/git/credentials"
+'
+
+XDG_CONFIG_HOME="$HOME/xdg"
+export XDG_CONFIG_HOME
+helper_test store
+unset XDG_CONFIG_HOME
+
+test_expect_success 'if custom xdg file exists, home and xdg files not created' '
+	test_when_finished "rm -f $HOME/xdg/git/credentials" &&
+	test -s "$HOME/xdg/git/credentials" &&
+	test_path_is_missing "$HOME/.git-credentials" &&
+	test_path_is_missing "$HOME/.config/git/credentials"
+'
+
+test_expect_success 'get: use home file if both home and xdg files have matches' '
+	echo "https://home-user:home-pass@example.com" >"$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	echo "https://xdg-user:xdg-pass@example.com" >"$HOME/.config/git/credentials" &&
+	check fill store <<-\EOF
+	protocol=https
+	host=example.com
+	--
+	protocol=https
+	host=example.com
+	username=home-user
+	password=home-pass
+	--
+	EOF
+'
+
+test_expect_success 'get: use xdg file if home file has no matches' '
+	>"$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	echo "https://xdg-user:xdg-pass@example.com" >"$HOME/.config/git/credentials" &&
+	check fill store <<-\EOF
+	protocol=https
+	host=example.com
+	--
+	protocol=https
+	host=example.com
+	username=xdg-user
+	password=xdg-pass
+	--
+	EOF
+'
+
+test_expect_success POSIXPERM 'get: use xdg file if home file is unreadable' '
+	echo "https://home-user:home-pass@example.com" >"$HOME/.git-credentials" &&
+	chmod -r "$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	echo "https://xdg-user:xdg-pass@example.com" >"$HOME/.config/git/credentials" &&
+	check fill store <<-\EOF
+	protocol=https
+	host=example.com
+	--
+	protocol=https
+	host=example.com
+	username=xdg-user
+	password=xdg-pass
+	--
+	EOF
+'
+
+test_expect_success 'store: if both xdg and home files exist, only store in home file' '
+	>"$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	>"$HOME/.config/git/credentials" &&
+	check approve store <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	echo "https://store-user:store-pass@example.com" >expected &&
+	test_cmp expected "$HOME/.git-credentials" &&
+	test_must_be_empty "$HOME/.config/git/credentials"
+'
+
+
+test_expect_success 'erase: erase matching credentials from both xdg and home files' '
+	echo "https://home-user:home-pass@example.com" >"$HOME/.git-credentials" &&
+	mkdir -p "$HOME/.config/git" &&
+	echo "https://xdg-user:xdg-pass@example.com" >"$HOME/.config/git/credentials" &&
+	check reject store <<-\EOF &&
+	protocol=https
+	host=example.com
+	EOF
+	test_must_be_empty "$HOME/.git-credentials" &&
+	test_must_be_empty "$HOME/.config/git/credentials"
+'
+
 test_done
diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index ab36b1eb72..93a4794930 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -47,6 +47,18 @@ $content"
 	test_cmp expect actual
     '
 
+    test_expect_success "Type of $type is correct using --allow-unknown-type" '
+	echo $type >expect &&
+	git cat-file -t --allow-unknown-type $sha1 >actual &&
+	test_cmp expect actual
+    '
+
+    test_expect_success "Size of $type is correct using --allow-unknown-type" '
+	echo $size >expect &&
+	git cat-file -s --allow-unknown-type $sha1 >actual &&
+	test_cmp expect actual
+    '
+
     test -z "$content" ||
     test_expect_success "Content of $type is correct" '
 	maybe_remove_timestamp "$content" $no_ts >expect &&
@@ -189,6 +201,13 @@ do
     '
 done
 
+for opt in t s e p
+do
+    test_expect_success "Passing -$opt with --follow-symlinks fails" '
+	    test_must_fail git cat-file --follow-symlinks -$opt $hello_sha1
+	'
+done
+
 test_expect_success "--batch-check for a non-existent named object" '
     test "foobar42 missing
 foobar84 missing" = \
@@ -296,4 +315,236 @@ test_expect_success '%(deltabase) reports packed delta bases' '
 	}
 '
 
+bogus_type="bogus"
+bogus_content="bogus"
+bogus_size=$(strlen "$bogus_content")
+bogus_sha1=$(echo_without_newline "$bogus_content" | git hash-object -t $bogus_type --literally -w --stdin)
+
+test_expect_success "Type of broken object is correct" '
+	echo $bogus_type >expect &&
+	git cat-file -t --allow-unknown-type $bogus_sha1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success "Size of broken object is correct" '
+	echo $bogus_size >expect &&
+	git cat-file -s --allow-unknown-type $bogus_sha1 >actual &&
+	test_cmp expect actual
+'
+bogus_type="abcdefghijklmnopqrstuvwxyz1234679"
+bogus_content="bogus"
+bogus_size=$(strlen "$bogus_content")
+bogus_sha1=$(echo_without_newline "$bogus_content" | git hash-object -t $bogus_type --literally -w --stdin)
+
+test_expect_success "Type of broken object is correct when type is large" '
+	echo $bogus_type >expect &&
+	git cat-file -t --allow-unknown-type $bogus_sha1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success "Size of large broken object is correct when type is large" '
+	echo $bogus_size >expect &&
+	git cat-file -s --allow-unknown-type $bogus_sha1 >actual &&
+	test_cmp expect actual
+'
+
+# Tests for git cat-file --follow-symlinks
+test_expect_success 'prep for symlink tests' '
+	echo_without_newline "$hello_content" >morx &&
+	test_ln_s_add morx same-dir-link &&
+	test_ln_s_add dir link-to-dir &&
+	test_ln_s_add ../fleem out-of-repo-link &&
+	test_ln_s_add .. out-of-repo-link-dir &&
+	test_ln_s_add same-dir-link link-to-link &&
+	test_ln_s_add nope broken-same-dir-link &&
+	mkdir dir &&
+	test_ln_s_add ../morx dir/parent-dir-link &&
+	test_ln_s_add .. dir/link-dir &&
+	test_ln_s_add ../../escape dir/out-of-repo-link &&
+	test_ln_s_add ../.. dir/out-of-repo-link-dir &&
+	test_ln_s_add nope dir/broken-link-in-dir &&
+	mkdir dir/subdir &&
+	test_ln_s_add ../../morx dir/subdir/grandparent-dir-link &&
+	test_ln_s_add ../../../great-escape dir/subdir/out-of-repo-link &&
+	test_ln_s_add ../../.. dir/subdir/out-of-repo-link-dir &&
+	test_ln_s_add ../../../ dir/subdir/out-of-repo-link-dir-trailing &&
+	test_ln_s_add ../parent-dir-link dir/subdir/parent-dir-link-to-link &&
+	echo_without_newline "$hello_content" >dir/subdir/ind2 &&
+	echo_without_newline "$hello_content" >dir/ind1 &&
+	test_ln_s_add dir dirlink &&
+	test_ln_s_add dir/subdir subdirlink &&
+	test_ln_s_add subdir/ind2 dir/link-to-child &&
+	test_ln_s_add dir/link-to-child link-to-down-link &&
+	test_ln_s_add dir/.. up-down &&
+	test_ln_s_add dir/../ up-down-trailing &&
+	test_ln_s_add dir/../morx up-down-file &&
+	test_ln_s_add dir/../../morx up-up-down-file &&
+	test_ln_s_add subdirlink/../../morx up-two-down-file &&
+	test_ln_s_add loop1 loop2 &&
+	test_ln_s_add loop2 loop1 &&
+	git add morx dir/subdir/ind2 dir/ind1 &&
+	git commit -am "test" &&
+	echo $hello_sha1 blob $hello_size >found
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for non-links' '
+	echo HEAD:morx | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo HEAD:nope missing >expect &&
+	echo HEAD:nope | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for in-repo, same-dir links' '
+	echo HEAD:same-dir-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for in-repo, links to dirs' '
+	echo HEAD:link-to-dir/ind1 | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for broken in-repo, same-dir links' '
+	echo dangling 25 >expect &&
+	echo HEAD:broken-same-dir-link >>expect &&
+	echo HEAD:broken-same-dir-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for same-dir links-to-links' '
+	echo HEAD:link-to-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for parent-dir links' '
+	echo HEAD:dir/parent-dir-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo notdir 29 >expect &&
+	echo HEAD:dir/parent-dir-link/nope >>expect &&
+	echo HEAD:dir/parent-dir-link/nope | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for .. links' '
+	echo dangling 22 >expect &&
+	echo HEAD:dir/link-dir/nope >>expect &&
+	echo HEAD:dir/link-dir/nope | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:dir/link-dir/morx | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo dangling 27 >expect &&
+	echo HEAD:dir/broken-link-in-dir >>expect &&
+	echo HEAD:dir/broken-link-in-dir | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for ../.. links' '
+	echo notdir 41 >expect &&
+	echo HEAD:dir/subdir/grandparent-dir-link/nope >>expect &&
+	echo HEAD:dir/subdir/grandparent-dir-link/nope | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:dir/subdir/grandparent-dir-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo HEAD:dir/subdir/parent-dir-link-to-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir/ links' '
+	echo dangling 17 >expect &&
+	echo HEAD:dirlink/morx >>expect &&
+	echo HEAD:dirlink/morx | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo $hello_sha1 blob $hello_size >expect &&
+	echo HEAD:dirlink/ind1 | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir/subdir links' '
+	echo dangling 20 >expect &&
+	echo HEAD:subdirlink/morx >>expect &&
+	echo HEAD:subdirlink/morx | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:subdirlink/ind2 | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir ->subdir links' '
+	echo notdir 27 >expect &&
+	echo HEAD:dir/link-to-child/morx >>expect &&
+	echo HEAD:dir/link-to-child/morx | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:dir/link-to-child | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo HEAD:link-to-down-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks' '
+	echo symlink 8 >expect &&
+	echo ../fleem >>expect &&
+	echo HEAD:out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo symlink 2 >expect &&
+	echo .. >>expect &&
+	echo HEAD:out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks in dirs' '
+	echo symlink 9 >expect &&
+	echo ../escape >>expect &&
+	echo HEAD:dir/out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo symlink 2 >expect &&
+	echo .. >>expect &&
+	echo HEAD:dir/out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks in subdirs' '
+	echo symlink 15 >expect &&
+	echo ../great-escape >>expect &&
+	echo HEAD:dir/subdir/out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo symlink 2 >expect &&
+	echo .. >>expect &&
+	echo HEAD:dir/subdir/out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo symlink 3 >expect &&
+	echo ../ >>expect &&
+	echo HEAD:dir/subdir/out-of-repo-link-dir-trailing | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlinks works for symlinks with internal ..' '
+	echo HEAD: | git cat-file --batch-check >expect &&
+	echo HEAD:up-down | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:up-down-trailing | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:up-down-file | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual &&
+	echo symlink 7 >expect &&
+	echo ../morx >>expect &&
+	echo HEAD:up-up-down-file | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual &&
+	echo HEAD:up-two-down-file | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp found actual
+'
+
+test_expect_success 'git cat-file --batch-check --follow-symlink breaks loops' '
+	echo loop 10 >expect &&
+	echo HEAD:loop1 >>expect &&
+	echo HEAD:loop1 | git cat-file --batch-check --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git cat-file --batch --follow-symlink returns correct sha and mode' '
+	echo HEAD:morx | git cat-file --batch >expect &&
+	echo HEAD:morx | git cat-file --batch --follow-symlinks >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index f83df8eb8b..7d2baa15bb 100755
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -201,4 +201,23 @@ test_expect_success 'corrupt tag' '
 	test_must_fail git hash-object -t tag --stdin </dev/null
 '
 
+test_expect_success 'hash-object complains about bogus type name' '
+	test_must_fail git hash-object -t bogus --stdin </dev/null
+'
+
+test_expect_success 'hash-object complains about truncated type name' '
+	test_must_fail git hash-object -t bl --stdin </dev/null
+'
+
+test_expect_success '--literally' '
+	t=1234567890 &&
+	echo example | git hash-object -t $t --literally --stdin
+'
+
+test_expect_success '--literally with extra-long type' '
+	t=12345678901234567890123456789012345678901234567890 &&
+	t="$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t" &&
+	echo example | git hash-object -t $t --literally --stdin
+'
+
 test_done
diff --git a/t/t1020-subdirectory.sh b/t/t1020-subdirectory.sh
index 2edb4f2de5..8e22b03cdd 100755
--- a/t/t1020-subdirectory.sh
+++ b/t/t1020-subdirectory.sh
@@ -162,16 +162,20 @@ test_expect_success 'no file/rev ambiguity check inside .git' '
 	)
 '
 
-test_expect_success 'no file/rev ambiguity check inside a bare repo' '
+test_expect_success 'no file/rev ambiguity check inside a bare repo (explicit GIT_DIR)' '
+	test_when_finished "rm -fr foo.git" &&
 	git clone -s --bare .git foo.git &&
 	(
 		cd foo.git &&
+		# older Git needed help by exporting GIT_DIR=.
+		# to realize that it is inside a bare repository.
+		# We keep this test around for regression testing.
 		GIT_DIR=. git show -s HEAD
 	)
 '
 
-# This still does not work as it should...
-: test_expect_success 'no file/rev ambiguity check inside a bare repo' '
+test_expect_success 'no file/rev ambiguity check inside a bare repo' '
+	test_when_finished "rm -fr foo.git" &&
 	git clone -s --bare .git foo.git &&
 	(
 		cd foo.git &&
@@ -180,7 +184,6 @@ test_expect_success 'no file/rev ambiguity check inside a bare repo' '
 '
 
 test_expect_success SYMLINKS 'detection should not be fooled by a symlink' '
-	rm -fr foo.git &&
 	git clone -s .git another &&
 	ln -s another yetanother &&
 	(
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 6805b9e6bb..ba89f4c009 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -519,7 +519,7 @@ test_expect_success 'stdin create ref works with path with space to blob' '
 test_expect_success 'stdin update ref fails with wrong old value' '
 	echo "update $c $m $m~1" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$c'"'"'" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
@@ -555,7 +555,7 @@ test_expect_success 'stdin update ref works with right old value' '
 test_expect_success 'stdin delete ref fails with wrong old value' '
 	echo "delete $a $m~1" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$a'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$a'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual
@@ -688,7 +688,7 @@ test_expect_success 'stdin update refs fails with wrong old value' '
 	update $c  ''
 	EOF
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual &&
@@ -883,7 +883,7 @@ test_expect_success 'stdin -z create ref works with path with space to blob' '
 test_expect_success 'stdin -z update ref fails with wrong old value' '
 	printf $F "update $c" "$m" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$c'"'"'" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
@@ -899,7 +899,7 @@ test_expect_success 'stdin -z create ref fails when ref exists' '
 	git rev-parse "$c" >expect &&
 	printf $F "create $c" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse "$c" >actual &&
 	test_cmp expect actual
 '
@@ -930,7 +930,7 @@ test_expect_success 'stdin -z update ref works with right old value' '
 test_expect_success 'stdin -z delete ref fails with wrong old value' '
 	printf $F "delete $a" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$a'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$a'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual
@@ -1045,7 +1045,7 @@ test_expect_success 'stdin -z update refs fails with wrong old value' '
 	git update-ref $c $m &&
 	printf $F "update $a" "$m" "$m" "update $b" "$m" "$m" "update $c" "$m" "$Z" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+	grep "fatal: Cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual &&
@@ -1065,4 +1065,32 @@ test_expect_success 'stdin -z delete refs works with packed and loose refs' '
 	test_must_fail git rev-parse --verify -q $c
 '
 
+run_with_limited_open_files () {
+	(ulimit -n 32 && "$@")
+}
+
+test_lazy_prereq ULIMIT_FILE_DESCRIPTORS 'run_with_limited_open_files true'
+
+test_expect_success ULIMIT_FILE_DESCRIPTORS 'large transaction creating branches does not burst open file limit' '
+(
+	for i in $(test_seq 33)
+	do
+		echo "create refs/heads/$i HEAD"
+	done >large_input &&
+	run_with_limited_open_files git update-ref --stdin <large_input &&
+	git rev-parse --verify -q refs/heads/33
+)
+'
+
+test_expect_success ULIMIT_FILE_DESCRIPTORS 'large transaction deleting branches does not burst open file limit' '
+(
+	for i in $(test_seq 33)
+	do
+		echo "delete refs/heads/$i HEAD"
+	done >large_input &&
+	run_with_limited_open_files git update-ref --stdin <large_input &&
+	test_must_fail git rev-parse --verify -q refs/heads/33
+)
+'
+
 test_done
diff --git a/t/t1404-update-ref-df-conflicts.sh b/t/t1404-update-ref-df-conflicts.sh
new file mode 100755
index 0000000000..66bafb5cf4
--- /dev/null
+++ b/t/t1404-update-ref-df-conflicts.sh
@@ -0,0 +1,107 @@
+#!/bin/sh
+
+test_description='Test git update-ref with D/F conflicts'
+. ./test-lib.sh
+
+test_update_rejected () {
+	prefix="$1" &&
+	before="$2" &&
+	pack="$3" &&
+	create="$4" &&
+	error="$5" &&
+	printf "create $prefix/%s $C\n" $before |
+	git update-ref --stdin &&
+	git for-each-ref $prefix >unchanged &&
+	if $pack
+	then
+		git pack-refs --all
+	fi &&
+	printf "create $prefix/%s $C\n" $create >input &&
+	test_must_fail git update-ref --stdin <input 2>output.err &&
+	grep -F "$error" output.err &&
+	git for-each-ref $prefix >actual &&
+	test_cmp unchanged actual
+}
+
+Q="'"
+
+test_expect_success 'setup' '
+
+	git commit --allow-empty -m Initial &&
+	C=$(git rev-parse HEAD)
+
+'
+
+test_expect_success 'existing loose ref is a simple prefix of new' '
+
+	prefix=refs/1l &&
+	test_update_rejected $prefix "a c e" false "b c/x d" \
+		"$Q$prefix/c$Q exists; cannot create $Q$prefix/c/x$Q"
+
+'
+
+test_expect_success 'existing packed ref is a simple prefix of new' '
+
+	prefix=refs/1p &&
+	test_update_rejected $prefix "a c e" true "b c/x d" \
+		"$Q$prefix/c$Q exists; cannot create $Q$prefix/c/x$Q"
+
+'
+
+test_expect_success 'existing loose ref is a deeper prefix of new' '
+
+	prefix=refs/2l &&
+	test_update_rejected $prefix "a c e" false "b c/x/y d" \
+		"$Q$prefix/c$Q exists; cannot create $Q$prefix/c/x/y$Q"
+
+'
+
+test_expect_success 'existing packed ref is a deeper prefix of new' '
+
+	prefix=refs/2p &&
+	test_update_rejected $prefix "a c e" true "b c/x/y d" \
+		"$Q$prefix/c$Q exists; cannot create $Q$prefix/c/x/y$Q"
+
+'
+
+test_expect_success 'new ref is a simple prefix of existing loose' '
+
+	prefix=refs/3l &&
+	test_update_rejected $prefix "a c/x e" false "b c d" \
+		"$Q$prefix/c/x$Q exists; cannot create $Q$prefix/c$Q"
+
+'
+
+test_expect_success 'new ref is a simple prefix of existing packed' '
+
+	prefix=refs/3p &&
+	test_update_rejected $prefix "a c/x e" true "b c d" \
+		"$Q$prefix/c/x$Q exists; cannot create $Q$prefix/c$Q"
+
+'
+
+test_expect_success 'new ref is a deeper prefix of existing loose' '
+
+	prefix=refs/4l &&
+	test_update_rejected $prefix "a c/x/y e" false "b c d" \
+		"$Q$prefix/c/x/y$Q exists; cannot create $Q$prefix/c$Q"
+
+'
+
+test_expect_success 'new ref is a deeper prefix of existing packed' '
+
+	prefix=refs/4p &&
+	test_update_rejected $prefix "a c/x/y e" true "b c d" \
+		"$Q$prefix/c/x/y$Q exists; cannot create $Q$prefix/c$Q"
+
+'
+
+test_expect_success 'one new ref is a simple prefix of another' '
+
+	prefix=refs/5 &&
+	test_update_rejected $prefix "a e" false "b c c/x d" \
+		"cannot process $Q$prefix/c$Q and $Q$prefix/c/x$Q at the same time"
+
+'
+
+test_done
diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
index 468e85621a..16d0b8bd1a 100755
--- a/t/t1430-bad-ref-name.sh
+++ b/t/t1430-bad-ref-name.sh
@@ -68,6 +68,14 @@ test_expect_success 'branch -D cannot delete non-ref in .git dir' '
 	test_cmp expect .git/my-private-file
 '
 
+test_expect_success 'branch -D cannot delete ref in .git dir' '
+	git rev-parse HEAD >.git/my-private-file &&
+	git rev-parse HEAD >expect &&
+	git branch foo/legit &&
+	test_must_fail git branch -D foo////./././../../../my-private-file &&
+	test_cmp expect .git/my-private-file
+'
+
 test_expect_success 'branch -D cannot delete absolute path' '
 	git branch -f extra &&
 	test_must_fail git branch -D "$(pwd)/.git/refs/heads/extra" &&
diff --git a/t/t1501-worktree.sh b/t/t1501-worktree.sh
index 8f36aa9fc4..cc5b870e58 100755
--- a/t/t1501-worktree.sh
+++ b/t/t1501-worktree.sh
@@ -346,4 +346,81 @@ test_expect_success 'relative $GIT_WORK_TREE and git subprocesses' '
 	test_cmp expected actual
 '
 
+test_expect_success 'Multi-worktree setup' '
+	mkdir work &&
+	mkdir -p repo.git/repos/foo &&
+	cp repo.git/HEAD repo.git/index repo.git/repos/foo &&
+	test_might_fail cp repo.git/sharedindex.* repo.git/repos/foo &&
+	sane_unset GIT_DIR GIT_CONFIG GIT_WORK_TREE
+'
+
+test_expect_success 'GIT_DIR set (1)' '
+	echo "gitdir: repo.git/repos/foo" >gitfile &&
+	echo ../.. >repo.git/repos/foo/commondir &&
+	(
+		cd work &&
+		GIT_DIR=../gitfile git rev-parse --git-common-dir >actual &&
+		test-path-utils real_path "$TRASH_DIRECTORY/repo.git" >expect &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'GIT_DIR set (2)' '
+	echo "gitdir: repo.git/repos/foo" >gitfile &&
+	echo "$(pwd)/repo.git" >repo.git/repos/foo/commondir &&
+	(
+		cd work &&
+		GIT_DIR=../gitfile git rev-parse --git-common-dir >actual &&
+		test-path-utils real_path "$TRASH_DIRECTORY/repo.git" >expect &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'Auto discovery' '
+	echo "gitdir: repo.git/repos/foo" >.git &&
+	echo ../.. >repo.git/repos/foo/commondir &&
+	(
+		cd work &&
+		git rev-parse --git-common-dir >actual &&
+		test-path-utils real_path "$TRASH_DIRECTORY/repo.git" >expect &&
+		test_cmp expect actual &&
+		echo haha >data1 &&
+		git add data1 &&
+		git ls-files --full-name :/ | grep data1 >actual &&
+		echo work/data1 >expect &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success '$GIT_DIR/common overrides core.worktree' '
+	mkdir elsewhere &&
+	git --git-dir=repo.git config core.worktree "$TRASH_DIRECTORY/elsewhere" &&
+	echo "gitdir: repo.git/repos/foo" >.git &&
+	echo ../.. >repo.git/repos/foo/commondir &&
+	(
+		cd work &&
+		git rev-parse --git-common-dir >actual &&
+		test-path-utils real_path "$TRASH_DIRECTORY/repo.git" >expect &&
+		test_cmp expect actual &&
+		echo haha >data2 &&
+		git add data2 &&
+		git ls-files --full-name :/ | grep data2 >actual &&
+		echo work/data2 >expect &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success '$GIT_WORK_TREE overrides $GIT_DIR/common' '
+	echo "gitdir: repo.git/repos/foo" >.git &&
+	echo ../.. >repo.git/repos/foo/commondir &&
+	(
+		cd work &&
+		echo haha >data3 &&
+		git --git-dir=../.git --work-tree=. add data3 &&
+		git ls-files --full-name -- :/ | grep data3 >actual &&
+		echo data3 >expect &&
+		test_cmp expect actual
+	)
+'
+
 test_done
diff --git a/t/t1509/prepare-chroot.sh b/t/t1509/prepare-chroot.sh
index 62691172e3..6d47e2c725 100755
--- a/t/t1509/prepare-chroot.sh
+++ b/t/t1509/prepare-chroot.sh
@@ -14,25 +14,45 @@ xmkdir() {
 
 R="$1"
 
+[ "$(id -u)" -eq 0 ] && die "This script should not be run as root, what if it does rm -rf /?"
 [ -n "$R" ] || die "usage: prepare-chroot.sh <root>"
 [ -x git ] || die "This script needs to be executed at git source code's top directory"
-[ -x /bin/busybox ] || die "You need busybox"
+if [ -x /bin/busybox ]; then
+	BB=/bin/busybox
+elif [ -x /usr/bin/busybox ]; then
+	BB=/usr/bin/busybox
+else
+	die "You need busybox"
+fi
 
 xmkdir "$R" "$R/bin" "$R/etc" "$R/lib" "$R/dev"
-[ -c "$R/dev/null" ] || die "/dev/null is missing. Do mknod $R/dev/null c 1 3 && chmod 666 $R/dev/null"
+touch "$R/dev/null"
 echo "root:x:0:0:root:/:/bin/sh" > "$R/etc/passwd"
 echo "$(id -nu):x:$(id -u):$(id -g)::$(pwd)/t:/bin/sh" >> "$R/etc/passwd"
 echo "root::0:root" > "$R/etc/group"
 echo "$(id -ng)::$(id -g):$(id -nu)" >> "$R/etc/group"
 
-[ -x "$R/bin/busybox" ] || cp /bin/busybox "$R/bin/busybox"
-[ -x "$R/bin/sh" ] || ln -s /bin/busybox "$R/bin/sh"
-[ -x "$R/bin/su" ] || ln -s /bin/busybox "$R/bin/su"
+[ -x "$R$BB" ] || cp $BB "$R/bin/busybox"
+for cmd in sh su ls expr tr basename rm mkdir mv id uname dirname cat true sed diff; do
+	ln -f -s /bin/busybox "$R/bin/$cmd"
+done
 
 mkdir -p "$R$(pwd)"
 rsync --exclude-from t/t1509/excludes -Ha . "$R$(pwd)"
-ldd git | grep '/' | sed 's,.*\s\(/[^ ]*\).*,\1,' | while read i; do
-	mkdir -p "$R$(dirname $i)"
-	cp "$i" "$R/$i"
+# Fake perl to reduce dependency, t1509 does not use perl, but some
+# env might slip through, see test-lib.sh, unset.*PERL_PATH
+sed 's|^PERL_PATH=.*|PERL_PATH=/bin/true|' GIT-BUILD-OPTIONS > "$R$(pwd)/GIT-BUILD-OPTIONS"
+for cmd in git $BB;do 
+	ldd $cmd | grep '/' | sed 's,.*\s\(/[^ ]*\).*,\1,' | while read i; do
+		mkdir -p "$R$(dirname $i)"
+		cp "$i" "$R/$i"
+	done
 done
-echo "Execute this in root: 'chroot $R /bin/su - $(id -nu)'"
+cat <<EOF
+All is set up in $R, execute t1509 with the following commands:
+
+sudo chroot $R /bin/su - $(id -nu)
+IKNOWWHATIAMDOING=YES ./t1509-root-worktree.sh -v -i
+
+When you are done, simply delete $R to clean up
+EOF
diff --git a/t/t1510-repo-setup.sh b/t/t1510-repo-setup.sh
index e1b2a99f10..33c1a587b3 100755
--- a/t/t1510-repo-setup.sh
+++ b/t/t1510-repo-setup.sh
@@ -106,6 +106,7 @@ setup_env () {
 expect () {
 	cat >"$1/expected" <<-EOF
 	setup: git_dir: $2
+	setup: git_common_dir: $2
 	setup: worktree: $3
 	setup: cwd: $4
 	setup: prefix: $5
diff --git a/t/t2025-checkout-to.sh b/t/t2025-checkout-to.sh
new file mode 100755
index 0000000000..f8e4df4818
--- /dev/null
+++ b/t/t2025-checkout-to.sh
@@ -0,0 +1,129 @@
+#!/bin/sh
+
+test_description='test git checkout --to'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit init
+'
+
+test_expect_success 'checkout --to not updating paths' '
+	test_must_fail git checkout --to -- init.t
+'
+
+test_expect_success 'checkout --to an existing worktree' '
+	mkdir -p existing/subtree &&
+	test_must_fail git checkout --detach --to existing master
+'
+
+test_expect_success 'checkout --to an existing empty worktree' '
+	mkdir existing_empty &&
+	git checkout --detach --to existing_empty master
+'
+
+test_expect_success 'checkout --to refuses to checkout locked branch' '
+	test_must_fail git checkout --to zere master &&
+	! test -d zere &&
+	! test -d .git/worktrees/zere
+'
+
+test_expect_success 'checkout --to a new worktree' '
+	git rev-parse HEAD >expect &&
+	git checkout --detach --to here master &&
+	(
+		cd here &&
+		test_cmp ../init.t init.t &&
+		test_must_fail git symbolic-ref HEAD &&
+		git rev-parse HEAD >actual &&
+		test_cmp ../expect actual &&
+		git fsck
+	)
+'
+
+test_expect_success 'checkout --to a new worktree from a subdir' '
+	(
+		mkdir sub &&
+		cd sub &&
+		git checkout --detach --to here master &&
+		cd here &&
+		test_cmp ../../init.t init.t
+	)
+'
+
+test_expect_success 'checkout --to from a linked checkout' '
+	(
+		cd here &&
+		git checkout --detach --to nested-here master &&
+		cd nested-here &&
+		git fsck
+	)
+'
+
+test_expect_success 'checkout --to a new worktree creating new branch' '
+	git checkout --to there -b newmaster master &&
+	(
+		cd there &&
+		test_cmp ../init.t init.t &&
+		git symbolic-ref HEAD >actual &&
+		echo refs/heads/newmaster >expect &&
+		test_cmp expect actual &&
+		git fsck
+	)
+'
+
+test_expect_success 'die the same branch is already checked out' '
+	(
+		cd here &&
+		test_must_fail git checkout newmaster
+	)
+'
+
+test_expect_success 'not die the same branch is already checked out' '
+	(
+		cd here &&
+		git checkout --ignore-other-worktrees --to anothernewmaster newmaster
+	)
+'
+
+test_expect_success 'not die on re-checking out current branch' '
+	(
+		cd there &&
+		git checkout newmaster
+	)
+'
+
+test_expect_success 'checkout --to from a bare repo' '
+	(
+		git clone --bare . bare &&
+		cd bare &&
+		git checkout --to ../there2 -b bare-master master
+	)
+'
+
+test_expect_success 'checkout from a bare repo without --to' '
+	(
+		cd bare &&
+		test_must_fail git checkout master
+	)
+'
+
+test_expect_success 'checkout with grafts' '
+	test_when_finished rm .git/info/grafts &&
+	test_commit abc &&
+	SHA1=`git rev-parse HEAD` &&
+	test_commit def &&
+	test_commit xyz &&
+	echo "`git rev-parse HEAD` $SHA1" >.git/info/grafts &&
+	cat >expected <<-\EOF &&
+	xyz
+	abc
+	EOF
+	git log --format=%s -2 >actual &&
+	test_cmp expected actual &&
+	git checkout --detach --to grafted master &&
+	git --git-dir=grafted/.git log --format=%s -2 >actual &&
+	test_cmp expected actual
+'
+
+test_done
diff --git a/t/t2026-prune-linked-checkouts.sh b/t/t2026-prune-linked-checkouts.sh
new file mode 100755
index 0000000000..1821a480c5
--- /dev/null
+++ b/t/t2026-prune-linked-checkouts.sh
@@ -0,0 +1,96 @@
+#!/bin/sh
+
+test_description='prune $GIT_DIR/worktrees'
+
+. ./test-lib.sh
+
+test_expect_success initialize '
+	git commit --allow-empty -m init
+'
+
+test_expect_success 'prune --worktrees on normal repo' '
+	git prune --worktrees &&
+	test_must_fail git prune --worktrees abc
+'
+
+test_expect_success 'prune files inside $GIT_DIR/worktrees' '
+	mkdir .git/worktrees &&
+	: >.git/worktrees/abc &&
+	git prune --worktrees --verbose >actual &&
+	cat >expect <<EOF &&
+Removing worktrees/abc: not a valid directory
+EOF
+	test_i18ncmp expect actual &&
+	! test -f .git/worktrees/abc &&
+	! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories without gitdir' '
+	mkdir -p .git/worktrees/def/abc &&
+	: >.git/worktrees/def/def &&
+	cat >expect <<EOF &&
+Removing worktrees/def: gitdir file does not exist
+EOF
+	git prune --worktrees --verbose >actual &&
+	test_i18ncmp expect actual &&
+	! test -d .git/worktrees/def &&
+	! test -d .git/worktrees
+'
+
+test_expect_success SANITY 'prune directories with unreadable gitdir' '
+	mkdir -p .git/worktrees/def/abc &&
+	: >.git/worktrees/def/def &&
+	: >.git/worktrees/def/gitdir &&
+	chmod u-r .git/worktrees/def/gitdir &&
+	git prune --worktrees --verbose >actual &&
+	test_i18ngrep "Removing worktrees/def: unable to read gitdir file" actual &&
+	! test -d .git/worktrees/def &&
+	! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories with invalid gitdir' '
+	mkdir -p .git/worktrees/def/abc &&
+	: >.git/worktrees/def/def &&
+	: >.git/worktrees/def/gitdir &&
+	git prune --worktrees --verbose >actual &&
+	test_i18ngrep "Removing worktrees/def: invalid gitdir file" actual &&
+	! test -d .git/worktrees/def &&
+	! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories with gitdir pointing to nowhere' '
+	mkdir -p .git/worktrees/def/abc &&
+	: >.git/worktrees/def/def &&
+	echo "$(pwd)"/nowhere >.git/worktrees/def/gitdir &&
+	git prune --worktrees --verbose >actual &&
+	test_i18ngrep "Removing worktrees/def: gitdir file points to non-existent location" actual &&
+	! test -d .git/worktrees/def &&
+	! test -d .git/worktrees
+'
+
+test_expect_success 'not prune locked checkout' '
+	test_when_finished rm -r .git/worktrees &&
+	mkdir -p .git/worktrees/ghi &&
+	: >.git/worktrees/ghi/locked &&
+	git prune --worktrees &&
+	test -d .git/worktrees/ghi
+'
+
+test_expect_success 'not prune recent checkouts' '
+	test_when_finished rm -r .git/worktrees &&
+	mkdir zz &&
+	mkdir -p .git/worktrees/jlm &&
+	echo "$(pwd)"/zz >.git/worktrees/jlm/gitdir &&
+	rmdir zz &&
+	git prune --worktrees --verbose --expire=2.days.ago &&
+	test -d .git/worktrees/jlm
+'
+
+test_expect_success 'not prune proper checkouts' '
+	test_when_finished rm -r .git/worktrees &&
+	git checkout "--to=$PWD/nop" --detach master &&
+	git prune --worktrees &&
+	test -d .git/worktrees/nop
+'
+
+test_done
diff --git a/t/t2203-add-intent.sh b/t/t2203-add-intent.sh
index 2a4a749b4f..7c641bfaf4 100755
--- a/t/t2203-add-intent.sh
+++ b/t/t2203-add-intent.sh
@@ -5,10 +5,24 @@ test_description='Intent to add'
 . ./test-lib.sh
 
 test_expect_success 'intent to add' '
+	test_commit 1 &&
+	git rm 1.t &&
+	echo hello >1.t &&
 	echo hello >file &&
 	echo hello >elif &&
 	git add -N file &&
-	git add elif
+	git add elif &&
+	git add -N 1.t
+'
+
+test_expect_success 'git status' '
+	git status --porcelain | grep -v actual >actual &&
+	cat >expect <<-\EOF &&
+	DA 1.t
+	A  elif
+	 A file
+	EOF
+	test_cmp expect actual
 '
 
 test_expect_success 'check result of "add -N"' '
@@ -43,7 +57,8 @@ test_expect_success 'i-t-a entry is simply ignored' '
 	git add -N nitfol &&
 	git commit -m second &&
 	test $(git ls-tree HEAD -- nitfol | wc -l) = 0 &&
-	test $(git diff --name-only HEAD -- nitfol | wc -l) = 1
+	test $(git diff --name-only HEAD -- nitfol | wc -l) = 0 &&
+	test $(git diff --name-only -- nitfol | wc -l) = 1
 '
 
 test_expect_success 'can commit with an unrelated i-t-a entry in index' '
@@ -72,13 +87,13 @@ test_expect_success 'cache-tree invalidates i-t-a paths' '
 	: >dir/bar &&
 	git add -N dir/bar &&
 	git diff --cached --name-only >actual &&
-	echo dir/bar >expect &&
+	>expect &&
 	test_cmp expect actual &&
 
 	git write-tree >/dev/null &&
 
 	git diff --cached --name-only >actual &&
-	echo dir/bar >expect &&
+	>expect &&
 	test_cmp expect actual
 '
 
diff --git a/t/t3033-merge-toplevel.sh b/t/t3033-merge-toplevel.sh
new file mode 100755
index 0000000000..46aadc410b
--- /dev/null
+++ b/t/t3033-merge-toplevel.sh
@@ -0,0 +1,136 @@
+#!/bin/sh
+
+test_description='"git merge" top-level frontend'
+
+. ./test-lib.sh
+
+t3033_reset () {
+	git checkout -B master two &&
+	git branch -f left three &&
+	git branch -f right four
+}
+
+test_expect_success setup '
+	test_commit one &&
+	git branch left &&
+	git branch right &&
+	test_commit two &&
+	git checkout left &&
+	test_commit three &&
+	git checkout right &&
+	test_commit four &&
+	git checkout master
+'
+
+# Local branches
+
+test_expect_success 'merge an octopus into void' '
+	t3033_reset &&
+	git checkout --orphan test &&
+	git rm -fr . &&
+	test_must_fail git merge left right &&
+	test_must_fail git rev-parse --verify HEAD &&
+	git diff --quiet &&
+	test_must_fail git rev-parse HEAD
+'
+
+test_expect_success 'merge an octopus, fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git merge left right &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^3 &&
+	git rev-parse HEAD^1 HEAD^2 | sort >actual &&
+	git rev-parse three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, non-fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git merge --no-ff left right &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse one three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, fast-forward (does not ff)' '
+	t3033_reset &&
+	git merge left right &&
+	# two (master) is not an ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge octopus, non-fast-forward' '
+	t3033_reset &&
+	git merge --no-ff left right &&
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+# The same set with FETCH_HEAD
+
+test_expect_success 'merge FETCH_HEAD octopus into void' '
+	t3033_reset &&
+	git checkout --orphan test &&
+	git rm -fr . &&
+	git fetch . left right &&
+	test_must_fail git merge FETCH_HEAD &&
+	test_must_fail git rev-parse --verify HEAD &&
+	git diff --quiet &&
+	test_must_fail git rev-parse HEAD
+'
+
+test_expect_success 'merge FETCH_HEAD octopus fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git fetch . left right &&
+	git merge FETCH_HEAD &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^3 &&
+	git rev-parse HEAD^1 HEAD^2 | sort >actual &&
+	git rev-parse three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus non-fast-forward (ff)' '
+	t3033_reset &&
+	git reset --hard one &&
+	git fetch . left right &&
+	git merge --no-ff FETCH_HEAD &&
+	# one is ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse one three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus fast-forward (does not ff)' '
+	t3033_reset &&
+	git fetch . left right &&
+	git merge FETCH_HEAD &&
+	# two (master) is not an ancestor of three (left) and four (right)
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge FETCH_HEAD octopus non-fast-forward' '
+	t3033_reset &&
+	git fetch . left right &&
+	git merge --no-ff FETCH_HEAD &&
+	test_must_fail git rev-parse --verify HEAD^4 &&
+	git rev-parse HEAD^1 HEAD^2 HEAD^3 | sort >actual &&
+	git rev-parse two three four | sort >expect &&
+	test_cmp expect actual
+'
+
+test_done
diff --git a/t/t3210-pack-refs.sh b/t/t3210-pack-refs.sh
index aa9eb3a3e5..8aae98d482 100755
--- a/t/t3210-pack-refs.sh
+++ b/t/t3210-pack-refs.sh
@@ -187,4 +187,21 @@ test_expect_success 'notice d/f conflict with existing ref' '
 	test_must_fail git branch foo/bar/baz/lots/of/extra/components
 '
 
+test_expect_success 'timeout if packed-refs.lock exists' '
+	LOCK=.git/packed-refs.lock &&
+	>"$LOCK" &&
+	test_when_finished "rm -f $LOCK" &&
+	test_must_fail git pack-refs --all --prune
+'
+
+test_expect_success 'retry acquiring packed-refs.lock' '
+	LOCK=.git/packed-refs.lock &&
+	>"$LOCK" &&
+	test_when_finished "wait; rm -f $LOCK" &&
+	{
+		( sleep 1 ; rm -f $LOCK ) &
+	} &&
+	git -c core.packedrefstimeout=3000 pack-refs --all --prune
+'
+
 test_done
diff --git a/t/t3402-rebase-merge.sh b/t/t3402-rebase-merge.sh
index 5a27ec9b5e..8f64505e4f 100755
--- a/t/t3402-rebase-merge.sh
+++ b/t/t3402-rebase-merge.sh
@@ -47,7 +47,7 @@ test_expect_success setup '
 '
 
 test_expect_success 'reference merge' '
-	git merge -s recursive "reference merge" HEAD master
+	git merge -s recursive -m "reference merge" master
 '
 
 PRE_REBASE=$(git rev-parse test-rebase)
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index eed76cca55..ac429a0bbb 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1055,4 +1055,51 @@ test_expect_success 'todo count' '
 	grep "^# Rebase ..* onto ..* ([0-9]" actual
 '
 
+test_expect_success 'rebase -i commits that overwrite untracked files (pick)' '
+	git checkout --force branch2 &&
+	git clean -f &&
+	set_fake_editor &&
+	FAKE_LINES="edit 1 2" git rebase -i A &&
+	test_cmp_rev HEAD F &&
+	test_path_is_missing file6 &&
+	>file6 &&
+	test_must_fail git rebase --continue &&
+	test_cmp_rev HEAD F &&
+	rm file6 &&
+	git rebase --continue &&
+	test_cmp_rev HEAD I
+'
+
+test_expect_success 'rebase -i commits that overwrite untracked files (squash)' '
+	git checkout --force branch2 &&
+	git clean -f &&
+	git tag original-branch2 &&
+	set_fake_editor &&
+	FAKE_LINES="edit 1 squash 2" git rebase -i A &&
+	test_cmp_rev HEAD F &&
+	test_path_is_missing file6 &&
+	>file6 &&
+	test_must_fail git rebase --continue &&
+	test_cmp_rev HEAD F &&
+	rm file6 &&
+	git rebase --continue &&
+	test $(git cat-file commit HEAD | sed -ne \$p) = I &&
+	git reset --hard original-branch2
+'
+
+test_expect_success 'rebase -i commits that overwrite untracked files (no ff)' '
+	git checkout --force branch2 &&
+	git clean -f &&
+	set_fake_editor &&
+	FAKE_LINES="edit 1 2" git rebase -i --no-ff A &&
+	test $(git cat-file commit HEAD | sed -ne \$p) = F &&
+	test_path_is_missing file6 &&
+	>file6 &&
+	test_must_fail git rebase --continue &&
+	test $(git cat-file commit HEAD | sed -ne \$p) = F &&
+	rm file6 &&
+	git rebase --continue &&
+	test $(git cat-file commit HEAD | sed -ne \$p) = I
+'
+
 test_done
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 24ddd8a704..deae948c76 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -326,15 +326,34 @@ test_expect_success 'split hunk "add -p (edit)"' '
 	# 2. Correct version applies the (not)edited version, and asks
 	#    about the next hunk, against which we say q and program
 	#    exits.
-	for a in s e     q n q q
-	do
-		echo $a
-	done |
+	printf "%s\n" s e     q n q q |
 	EDITOR=: git add -p &&
 	git diff >actual &&
 	! grep "^+15" actual
 '
 
+test_expect_failure 'split hunk "add -p (no, yes, edit)"' '
+	cat >test <<-\EOF &&
+	5
+	10
+	20
+	21
+	30
+	31
+	40
+	50
+	60
+	EOF
+	git reset &&
+	# test sequence is s(plit), n(o), y(es), e(dit)
+	# q n q q is there to make sure we exit at the end.
+	printf "%s\n" s n y e   q n q q |
+	EDITOR=: git add -p 2>error &&
+	test_must_be_empty error &&
+	git diff >actual &&
+	! grep "^+31" actual
+'
+
 test_expect_success 'patch mode ignores unmerged entries' '
 	git reset --hard &&
 	test_commit conflict &&
diff --git a/t/t3702-add-edit.sh b/t/t3702-add-edit.sh
index 4ee47cc9a8..3cb74ca296 100755
--- a/t/t3702-add-edit.sh
+++ b/t/t3702-add-edit.sh
@@ -118,4 +118,11 @@ test_expect_success 'add -e' '
 
 '
 
+test_expect_success 'add -e notices editor failure' '
+	git reset --hard &&
+	echo change >>file &&
+	test_must_fail env GIT_EDITOR=false git add -e &&
+	test_expect_code 1 git diff --exit-code
+'
+
 test_done
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 1e29962fad..7396ca9911 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -10,6 +10,8 @@ test_description='Test git stash'
 test_expect_success 'stash some dirty working directory' '
 	echo 1 > file &&
 	git add file &&
+	echo unrelated >other-file &&
+	git add other-file &&
 	test_tick &&
 	git commit -m initial &&
 	echo 2 > file &&
@@ -43,10 +45,15 @@ test_expect_success 'applying bogus stash does nothing' '
 	test_cmp expect file
 '
 
+test_expect_success 'apply requires a clean index' '
+	test_when_finished "git reset --hard" &&
+	echo changed >other-file &&
+	git add other-file &&
+	test_must_fail git stash apply
+'
+
 test_expect_success 'apply does not need clean working directory' '
 	echo 4 >other-file &&
-	git add other-file &&
-	echo 5 >other-file &&
 	git stash apply &&
 	echo 3 >expect &&
 	test_cmp expect file
@@ -93,6 +100,10 @@ test_expect_success 'unstashing in a subdirectory' '
 	)
 '
 
+test_expect_success 'stash drop complains of extra options' '
+	test_must_fail git stash drop --foo
+'
+
 test_expect_success 'drop top stash' '
 	git reset --hard &&
 	git stash list > stashlist1 &&
@@ -695,8 +706,8 @@ test_expect_success 'setup stash with index and worktree changes' '
 '
 
 test_expect_success 'stash list implies --first-parent -m' '
-	cat >expect <<-\EOF &&
-	stash@{0}: WIP on master: b27a2bc subdir
+	cat >expect <<-EOF &&
+	stash@{0}
 
 	diff --git a/file b/file
 	index 257cc56..d26b33d 100644
@@ -706,13 +717,13 @@ test_expect_success 'stash list implies --first-parent -m' '
 	-foo
 	+working
 	EOF
-	git stash list -p >actual &&
+	git stash list --format=%gd -p >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'stash list --cc shows combined diff' '
 	cat >expect <<-\EOF &&
-	stash@{0}: WIP on master: b27a2bc subdir
+	stash@{0}
 
 	diff --cc file
 	index 257cc56,9015a7a..d26b33d
@@ -723,7 +734,7 @@ test_expect_success 'stash list --cc shows combined diff' '
 	 -index
 	++working
 	EOF
-	git stash list -p --cc >actual &&
+	git stash list --format=%gd -p --cc >actual &&
 	test_cmp expect actual
 '
 
diff --git a/t/t3904-stash-patch.sh b/t/t3904-stash-patch.sh
index 70655c1848..38e730090f 100755
--- a/t/t3904-stash-patch.sh
+++ b/t/t3904-stash-patch.sh
@@ -1,9 +1,15 @@
 #!/bin/sh
 
-test_description='git checkout --patch'
+test_description='stash -p'
 . ./lib-patch-mode.sh
 
-test_expect_success PERL 'setup' '
+if ! test_have_prereq PERL
+then
+	skip_all='skipping stash -p tests, perl not available'
+	test_done
+fi
+
+test_expect_success 'setup' '
 	mkdir dir &&
 	echo parent > dir/foo &&
 	echo dummy > bar &&
@@ -20,7 +26,7 @@ test_expect_success PERL 'setup' '
 
 # note: order of files with unstaged changes: HEAD bar dir/foo
 
-test_expect_success PERL 'saying "n" does nothing' '
+test_expect_success 'saying "n" does nothing' '
 	set_state HEAD HEADfile_work HEADfile_index &&
 	set_state dir/foo work index &&
 	(echo n; echo n; echo n) | test_must_fail git stash save -p &&
@@ -29,7 +35,7 @@ test_expect_success PERL 'saying "n" does nothing' '
 	verify_state dir/foo work index
 '
 
-test_expect_success PERL 'git stash -p' '
+test_expect_success 'git stash -p' '
 	(echo y; echo n; echo y) | git stash save -p &&
 	verify_state HEAD committed HEADfile_index &&
 	verify_saved_state bar &&
@@ -41,7 +47,7 @@ test_expect_success PERL 'git stash -p' '
 	verify_state dir/foo work head
 '
 
-test_expect_success PERL 'git stash -p --no-keep-index' '
+test_expect_success 'git stash -p --no-keep-index' '
 	set_state HEAD HEADfile_work HEADfile_index &&
 	set_state bar bar_work bar_index &&
 	set_state dir/foo work index &&
@@ -56,7 +62,7 @@ test_expect_success PERL 'git stash -p --no-keep-index' '
 	verify_state dir/foo work index
 '
 
-test_expect_success PERL 'git stash --no-keep-index -p' '
+test_expect_success 'git stash --no-keep-index -p' '
 	set_state HEAD HEADfile_work HEADfile_index &&
 	set_state bar bar_work bar_index &&
 	set_state dir/foo work index &&
@@ -71,8 +77,31 @@ test_expect_success PERL 'git stash --no-keep-index -p' '
 	verify_state dir/foo work index
 '
 
-test_expect_success PERL 'none of this moved HEAD' '
+test_expect_success 'none of this moved HEAD' '
 	verify_saved_head
 '
 
+test_expect_failure 'stash -p with split hunk' '
+	git reset --hard &&
+	cat >test <<-\EOF &&
+	aaa
+	bbb
+	ccc
+	EOF
+	git add test &&
+	git commit -m "initial" &&
+	cat >test <<-\EOF &&
+	aaa
+	added line 1
+	bbb
+	added line 2
+	ccc
+	EOF
+	printf "%s\n" s n y q |
+	test_might_fail git stash -p 2>error &&
+	! test_must_be_empty error &&
+	grep "added line 1" test &&
+	! grep "added line 2" test
+'
+
 test_done
diff --git a/t/t4011-diff-symlink.sh b/t/t4011-diff-symlink.sh
index 13e7f621ab..7452fce0da 100755
--- a/t/t4011-diff-symlink.sh
+++ b/t/t4011-diff-symlink.sh
@@ -139,11 +139,13 @@ test_expect_success SYMLINKS 'setup symlinks with attributes' '
 test_expect_success SYMLINKS 'symlinks do not respect userdiff config by path' '
 	cat >expect <<-\EOF &&
 	diff --git a/file.bin b/file.bin
-	index e69de29..d95f3ad 100644
-	Binary files a/file.bin and b/file.bin differ
+	new file mode 100644
+	index 0000000..d95f3ad
+	Binary files /dev/null and b/file.bin differ
 	diff --git a/link.bin b/link.bin
-	index e69de29..dce41ec 120000
-	--- a/link.bin
+	new file mode 120000
+	index 0000000..dce41ec
+	--- /dev/null
 	+++ b/link.bin
 	@@ -0,0 +1 @@
 	+file.bin
diff --git a/t/t4013/diff.log_--decorate=full_--all b/t/t4013/diff.log_--decorate=full_--all
index 44d45257da..b345b2ebfa 100644
--- a/t/t4013/diff.log_--decorate=full_--all
+++ b/t/t4013/diff.log_--decorate=full_--all
@@ -5,7 +5,7 @@ Date:   Mon Jun 26 00:06:00 2006 +0000
 
     Rearranged lines in dir/sub
 
-commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (HEAD, refs/heads/master)
+commit 59d314ad6f356dd08601a4cd5e530381da3e3c64 (HEAD -> refs/heads/master)
 Merge: 9a6d494 c7a2ab9
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:04:00 2006 +0000
diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh
index 075ece6db1..6eb83211b5 100755
--- a/t/t4053-diff-no-index.sh
+++ b/t/t4053-diff-no-index.sh
@@ -55,4 +55,38 @@ test_expect_success 'git diff --no-index executed outside repo gives correct err
 	)
 '
 
+test_expect_success 'diff D F and diff F D' '
+	(
+		cd repo &&
+		echo in-repo >a &&
+		echo non-repo >../non/git/a &&
+		mkdir sub &&
+		echo sub-repo >sub/a &&
+
+		test_must_fail git diff --no-index sub/a ../non/git/a >expect &&
+		test_must_fail git diff --no-index sub/a ../non/git/ >actual &&
+		test_cmp expect actual &&
+
+		test_must_fail git diff --no-index a ../non/git/a >expect &&
+		test_must_fail git diff --no-index a ../non/git/ >actual &&
+		test_cmp expect actual &&
+
+		test_must_fail git diff --no-index ../non/git/a a >expect &&
+		test_must_fail git diff --no-index ../non/git a >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'turning a file into a directory' '
+	(
+		cd non/git &&
+		mkdir d e e/sub &&
+		echo 1 >d/sub &&
+		echo 2 >e/sub/file &&
+		printf "D\td/sub\nA\te/sub/file\n" >expect &&
+		test_must_fail git diff --no-index --name-status d e >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 0901b30982..4451127eb2 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -54,14 +54,14 @@ canned_test "-L 4:a.c -L 8,12:a.c simple" multiple-superset
 canned_test "-L 8,12:a.c -L 4:a.c simple" multiple-superset
 
 test_bad_opts "-L" "switch.*requires a value"
-test_bad_opts "-L b.c" "argument.*not of the form"
-test_bad_opts "-L 1:" "argument.*not of the form"
+test_bad_opts "-L b.c" "argument not .start,end:file"
+test_bad_opts "-L 1:" "argument not .start,end:file"
 test_bad_opts "-L 1:nonexistent" "There is no path"
 test_bad_opts "-L 1:simple" "There is no path"
-test_bad_opts "-L '/foo:b.c'" "argument.*not of the form"
+test_bad_opts "-L '/foo:b.c'" "argument not .start,end:file"
 test_bad_opts "-L 1000:b.c" "has only.*lines"
 test_bad_opts "-L 1,1000:b.c" "has only.*lines"
-test_bad_opts "-L :b.c" "argument.*not of the form"
+test_bad_opts "-L :b.c" "argument not .start,end:file"
 test_bad_opts "-L :foo:b.c" "no match"
 
 test_expect_success '-L X (X == nlines)' '
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 227d293350..7efd45bc27 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -9,36 +9,27 @@ modify () {
 	mv "$2.x" "$2"
 }
 
-D=`pwd`
-
 test_expect_success setup '
-
 	echo file >file &&
 	git add file &&
 	git commit -a -m original
-
 '
 
 test_expect_success 'pulling into void' '
-	mkdir cloned &&
-	cd cloned &&
-	git init &&
-	git pull ..
-'
-
-cd "$D"
-
-test_expect_success 'checking the results' '
+	git init cloned &&
+	(
+		cd cloned &&
+		git pull ..
+	) &&
 	test -f file &&
 	test -f cloned/file &&
 	test_cmp file cloned/file
 '
 
 test_expect_success 'pulling into void using master:master' '
-	mkdir cloned-uho &&
+	git init cloned-uho &&
 	(
 		cd cloned-uho &&
-		git init &&
 		git pull .. master:master
 	) &&
 	test -f file &&
@@ -71,7 +62,6 @@ test_expect_success 'pulling into void does not overwrite staged files' '
 	)
 '
 
-
 test_expect_success 'pulling into void does not remove new staged files' '
 	git init cloned-staged-new &&
 	(
@@ -86,6 +76,15 @@ test_expect_success 'pulling into void does not remove new staged files' '
 	)
 '
 
+test_expect_success 'pulling into void must not create an octopus' '
+	git init cloned-octopus &&
+	(
+		cd cloned-octopus &&
+		test_must_fail git pull .. master master &&
+		! test -f file
+	)
+'
+
 test_expect_success 'test . as a remote' '
 
 	git branch copy master &&
diff --git a/t/t5524-pull-msg.sh b/t/t5524-pull-msg.sh
index 8cccecc2fc..c278adaa5a 100755
--- a/t/t5524-pull-msg.sh
+++ b/t/t5524-pull-msg.sh
@@ -17,6 +17,9 @@ test_expect_success setup '
 		git commit -m "add bfile"
 	) &&
 	test_tick && test_tick &&
+	echo "second" >afile &&
+	git add afile &&
+	git commit -m "second commit" &&
 	echo "original $dollar" >afile &&
 	git add afile &&
 	git commit -m "do not clobber $dollar signs"
@@ -32,4 +35,18 @@ test_expect_success pull '
 )
 '
 
+test_expect_success '--log=1 limits shortlog length' '
+(
+	cd cloned &&
+	git reset --hard HEAD^ &&
+	test "$(cat afile)" = original &&
+	test "$(cat bfile)" = added &&
+	git pull --log=1 &&
+	git log -3 &&
+	git cat-file commit HEAD >result &&
+	grep Dollar result &&
+	! grep "second commit" result
+)
+'
+
 test_done
diff --git a/t/t5539-fetch-http-shallow.sh b/t/t5539-fetch-http-shallow.sh
index b46118846c..37a433504e 100755
--- a/t/t5539-fetch-http-shallow.sh
+++ b/t/t5539-fetch-http-shallow.sh
@@ -3,12 +3,6 @@
 test_description='fetch/clone from a shallow clone over http'
 
 . ./test-lib.sh
-
-if test -n "$NO_CURL"; then
-	skip_all='skipping test, git built without http support'
-	test_done
-fi
-
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t5541-http-push-smart.sh b/t/t5541-http-push-smart.sh
index 9cf27e8c99..fd7d06b9a2 100755
--- a/t/t5541-http-push-smart.sh
+++ b/t/t5541-http-push-smart.sh
@@ -6,11 +6,6 @@
 test_description='test smart pushing over http via http-backend'
 . ./test-lib.sh
 
-if test -n "$NO_CURL"; then
-	skip_all='skipping test, git built without http support'
-	test_done
-fi
-
 ROOT_PATH="$PWD"
 . "$TEST_DIRECTORY"/lib-gpg.sh
 . "$TEST_DIRECTORY"/lib-httpd.sh
diff --git a/t/t5542-push-http-shallow.sh b/t/t5542-push-http-shallow.sh
index 2a691e09eb..5165833157 100755
--- a/t/t5542-push-http-shallow.sh
+++ b/t/t5542-push-http-shallow.sh
@@ -3,12 +3,6 @@
 test_description='push from/to a shallow clone over http'
 
 . ./test-lib.sh
-
-if test -n "$NO_CURL"; then
-	say 'skipping test, git built without http support'
-	test_done
-fi
-
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 3d11b7a6bb..87a7aa04ae 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -2,12 +2,6 @@
 
 test_description='test dumb fetching over http via static file'
 . ./test-lib.sh
-
-if test -n "$NO_CURL"; then
-	skip_all='skipping test, git built without http support'
-	test_done
-fi
-
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 66439e58fc..58207d8825 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -2,12 +2,6 @@
 
 test_description='test smart fetching over http via http-backend'
 . ./test-lib.sh
-
-if test -n "$NO_CURL"; then
-	skip_all='skipping test, git built without http support'
-	test_done
-fi
-
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
@@ -224,27 +218,35 @@ test_expect_success 'transfer.hiderefs works over smart-http' '
 	git -C hidden.git rev-parse --verify b
 '
 
-test_expect_success 'create 2,000 tags in the repo' '
-	(
-	cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
-	for i in $(test_seq 2000)
+# create an arbitrary number of tags, numbered from tag-$1 to tag-$2
+create_tags () {
+	rm -f marks &&
+	for i in $(test_seq "$1" "$2")
 	do
-		echo "commit refs/heads/too-many-refs"
-		echo "mark :$i"
-		echo "committer git <git@example.com> $i +0000"
-		echo "data 0"
-		echo "M 644 inline bla.txt"
-		echo "data 4"
-		echo "bla"
+		# don't use here-doc, because it requires a process
+		# per loop iteration
+		echo "commit refs/heads/too-many-refs-$1" &&
+		echo "mark :$i" &&
+		echo "committer git <git@example.com> $i +0000" &&
+		echo "data 0" &&
+		echo "M 644 inline bla.txt" &&
+		echo "data 4" &&
+		echo "bla" &&
 		# make every commit dangling by always
 		# rewinding the branch after each commit
-		echo "reset refs/heads/too-many-refs"
-		echo "from :1"
+		echo "reset refs/heads/too-many-refs-$1" &&
+		echo "from :$1"
 	done | git fast-import --export-marks=marks &&
 
 	# now assign tags to all the dangling commits we created above
 	tag=$(perl -e "print \"bla\" x 30") &&
 	sed -e "s|^:\([^ ]*\) \(.*\)$|\2 refs/tags/$tag-\1|" <marks >>packed-refs
+}
+
+test_expect_success 'create 2,000 tags in the repo' '
+	(
+		cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+		create_tags 1 2000
 	)
 '
 
@@ -265,5 +267,20 @@ test_expect_success 'large fetch-pack requests can be split across POSTs' '
 	test_line_count = 2 posts
 '
 
+test_expect_success EXPENSIVE 'http can handle enormous ref negotiation' '
+	(
+		cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+		create_tags 2001 50000
+	) &&
+	git -C too-many-refs fetch -q --tags &&
+	(
+		cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+		create_tags 50001 100000
+	) &&
+	git -C too-many-refs fetch -q --tags &&
+	git -C too-many-refs for-each-ref refs/tags >tags &&
+	test_line_count = 100000 tags
+'
+
 stop_httpd
 test_done
diff --git a/t/t5561-http-backend.sh b/t/t5561-http-backend.sh
index d23fb02384..19afe96698 100755
--- a/t/t5561-http-backend.sh
+++ b/t/t5561-http-backend.sh
@@ -2,12 +2,6 @@
 
 test_description='test git-http-backend'
 . ./test-lib.sh
-
-if test -n "$NO_CURL"; then
-	skip_all='skipping test, git built without http support'
-	test_done
-fi
-
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 1befc453a3..bfdaf75966 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -296,6 +296,12 @@ setup_ssh_wrapper () {
 	'
 }
 
+copy_ssh_wrapper_as () {
+	cp "$TRASH_DIRECTORY/ssh-wrapper" "$1" &&
+	GIT_SSH="$1" &&
+	export GIT_SSH
+}
+
 expect_ssh () {
 	test_when_finished '
 		(cd "$TRASH_DIRECTORY" && rm -f ssh-expect && >ssh-output)
@@ -332,9 +338,36 @@ test_expect_success !MINGW,!CYGWIN 'clone local path foo:bar' '
 
 test_expect_success 'bracketed hostnames are still ssh' '
 	git clone "[myhost:123]:src" ssh-bracket-clone &&
-	expect_ssh myhost '-p 123' src
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'uplink is not treated as putty' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/uplink" &&
+	git clone "[myhost:123]:src" ssh-bracket-clone-uplink &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'plink is treated specially (as putty)' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	git clone "[myhost:123]:src" ssh-bracket-clone-plink-0 &&
+	expect_ssh "-P 123" myhost src
 '
 
+test_expect_success 'plink.exe is treated specially (as putty)' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	git clone "[myhost:123]:src" ssh-bracket-clone-plink-1 &&
+	expect_ssh "-P 123" myhost src
+'
+
+test_expect_success 'tortoiseplink is like putty, with extra arguments' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/tortoiseplink" &&
+	git clone "[myhost:123]:src" ssh-bracket-clone-plink-2 &&
+	expect_ssh "-batch -P 123" myhost src
+'
+
+# Reset the GIT_SSH environment variable for clone tests.
+setup_ssh_wrapper
+
 counter=0
 # $1 url
 # $2 none|host
diff --git a/t/t6020-merge-df.sh b/t/t6020-merge-df.sh
index 27c3d73961..2af1beec5f 100755
--- a/t/t6020-merge-df.sh
+++ b/t/t6020-merge-df.sh
@@ -24,7 +24,7 @@ test_expect_success 'prepare repository' '
 '
 
 test_expect_success 'Merge with d/f conflicts' '
-	test_expect_code 1 git merge "merge msg" B master
+	test_expect_code 1 git merge -m "merge msg" master
 '
 
 test_expect_success 'F/D conflict' '
diff --git a/t/t6021-merge-criss-cross.sh b/t/t6021-merge-criss-cross.sh
index d15b313d4b..213deecab1 100755
--- a/t/t6021-merge-criss-cross.sh
+++ b/t/t6021-merge-criss-cross.sh
@@ -48,7 +48,7 @@ echo "1
 " > file &&
 git commit -m "C3" file &&
 git branch C3 &&
-git merge "pre E3 merge" B A &&
+git merge -m "pre E3 merge" A &&
 echo "1
 2
 3 changed in E3, branch B. New file size
@@ -61,7 +61,7 @@ echo "1
 " > file &&
 git commit -m "E3" file &&
 git checkout A &&
-git merge "pre D8 merge" A C3 &&
+git merge -m "pre D8 merge" C3 &&
 echo "1
 2
 3 changed in C3, branch B
@@ -73,7 +73,7 @@ echo "1
 9" > file &&
 git commit -m D8 file'
 
-test_expect_success 'Criss-cross merge' 'git merge "final merge" A B'
+test_expect_success 'Criss-cross merge' 'git merge -m "final merge" B'
 
 cat > file-expect <<EOF
 1
diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index 66643e4bd7..855afda80a 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -394,4 +394,14 @@ test_expect_success 'replace submodule revision' '
 	test $orig_head != `git show-ref --hash --head HEAD`
 '
 
+test_expect_success 'filter commit message without trailing newline' '
+	git reset --hard original &&
+	commit=$(printf "no newline" | git commit-tree HEAD^{tree}) &&
+	git update-ref refs/heads/no-newline $commit &&
+	git filter-branch -f refs/heads/no-newline &&
+	echo $commit >expect &&
+	git rev-parse refs/heads/no-newline >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index fa207f3b8c..d1ff5c94f2 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1491,10 +1491,10 @@ run_with_limited_stack () {
 	(ulimit -s 128 && "$@")
 }
 
-test_lazy_prereq ULIMIT 'run_with_limited_stack true'
+test_lazy_prereq ULIMIT_STACK_SIZE 'run_with_limited_stack true'
 
 # we require ulimit, this excludes Windows
-test_expect_success ULIMIT '--contains works in a deep repo' '
+test_expect_success ULIMIT_STACK_SIZE '--contains works in a deep repo' '
 	>expect &&
 	i=1 &&
 	while test $i -lt 8000
diff --git a/t/t7061-wtstatus-ignore.sh b/t/t7061-wtstatus-ignore.sh
index 460789b4d8..cdc0747bf0 100755
--- a/t/t7061-wtstatus-ignore.sh
+++ b/t/t7061-wtstatus-ignore.sh
@@ -20,6 +20,15 @@ test_expect_success 'status untracked directory with --ignored' '
 	test_cmp expected actual
 '
 
+test_expect_success 'same with gitignore starting with BOM' '
+	printf "\357\273\277ignored\n" >.gitignore &&
+	mkdir -p untracked &&
+	: >untracked/ignored &&
+	: >untracked/uncommitted &&
+	git status --porcelain --ignored >actual &&
+	test_cmp expected actual
+'
+
 cat >expected <<\EOF
 ?? .gitignore
 ?? actual
diff --git a/t/t7063-status-untracked-cache.sh b/t/t7063-status-untracked-cache.sh
new file mode 100755
index 0000000000..bd4806c12a
--- /dev/null
+++ b/t/t7063-status-untracked-cache.sh
@@ -0,0 +1,357 @@
+#!/bin/sh
+
+test_description='test untracked cache'
+
+. ./test-lib.sh
+
+avoid_racy() {
+	sleep 1
+}
+
+# It's fine if git update-index returns an error code other than one,
+# it'll be caught in the first test.
+test_lazy_prereq UNTRACKED_CACHE '
+	{ git update-index --untracked-cache; ret=$?; } &&
+	test $ret -ne 1
+'
+
+if ! test_have_prereq UNTRACKED_CACHE; then
+	skip_all='This system does not support untracked cache'
+	test_done
+fi
+
+test_expect_success 'setup' '
+	git init worktree &&
+	cd worktree &&
+	mkdir done dtwo dthree &&
+	touch one two three done/one dtwo/two dthree/three &&
+	git add one two done/one &&
+	: >.git/info/exclude &&
+	git update-index --untracked-cache
+'
+
+test_expect_success 'untracked cache is empty' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 0000000000000000000000000000000000000000
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+EOF
+	test_cmp ../expect ../actual
+'
+
+cat >../status.expect <<EOF &&
+A  done/one
+A  one
+A  two
+?? dthree/
+?? dtwo/
+?? three
+EOF
+
+cat >../dump.expect <<EOF &&
+info/exclude e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ 0000000000000000000000000000000000000000 recurse valid
+dthree/
+dtwo/
+three
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+three
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+
+test_expect_success 'status first time (empty cache)' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 3
+gitignore invalidation: 1
+directory invalidation: 0
+opendir: 4
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'untracked cache after first status' '
+	test-dump-untracked-cache >../actual &&
+	test_cmp ../dump.expect ../actual
+'
+
+test_expect_success 'status second time (fully populated cache)' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 0
+opendir: 0
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'untracked cache after second status' '
+	test-dump-untracked-cache >../actual &&
+	test_cmp ../dump.expect ../actual
+'
+
+test_expect_success 'modify in root directory, one dir invalidation' '
+	avoid_racy &&
+	: >four &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	cat >../status.expect <<EOF &&
+A  done/one
+A  one
+A  two
+?? dthree/
+?? dtwo/
+?? four
+?? three
+EOF
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 1
+opendir: 1
+EOF
+	test_cmp ../trace.expect ../trace
+
+'
+
+test_expect_success 'verify untracked cache dump' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ 0000000000000000000000000000000000000000 recurse valid
+dthree/
+dtwo/
+four
+three
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+three
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'new .gitignore invalidates recursively' '
+	avoid_racy &&
+	echo four >.gitignore &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	cat >../status.expect <<EOF &&
+A  done/one
+A  one
+A  two
+?? .gitignore
+?? dthree/
+?? dtwo/
+?? three
+EOF
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 1
+directory invalidation: 1
+opendir: 4
+EOF
+	test_cmp ../trace.expect ../trace
+
+'
+
+test_expect_success 'verify untracked cache dump' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dthree/
+dtwo/
+three
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+three
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'new info/exclude invalidates everything' '
+	avoid_racy &&
+	echo three >>.git/info/exclude &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	cat >../status.expect <<EOF &&
+A  done/one
+A  one
+A  two
+?? .gitignore
+?? dtwo/
+EOF
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 1
+directory invalidation: 0
+opendir: 4
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'verify untracked cache dump' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dtwo/
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'move two from tracked to untracked' '
+	git rm --cached two &&
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'status after the move' '
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	cat >../status.expect <<EOF &&
+A  done/one
+A  one
+?? .gitignore
+?? dtwo/
+?? two
+EOF
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 0
+opendir: 1
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'verify untracked cache dump' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dtwo/
+two
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'move two from untracked to tracked' '
+	git add two &&
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'status after the move' '
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../actual &&
+	cat >../status.expect <<EOF &&
+A  done/one
+A  one
+A  two
+?? .gitignore
+?? dtwo/
+EOF
+	test_cmp ../status.expect ../actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 0
+opendir: 1
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'verify untracked cache dump' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dtwo/
+/done/ 0000000000000000000000000000000000000000 recurse valid
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_done
diff --git a/t/t7410-submodule-checkout-to.sh b/t/t7410-submodule-checkout-to.sh
new file mode 100755
index 0000000000..8f30aed6cc
--- /dev/null
+++ b/t/t7410-submodule-checkout-to.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+
+test_description='Combination of submodules and multiple workdirs'
+
+. ./test-lib.sh
+
+base_path=$(pwd -P)
+
+test_expect_success 'setup: make origin' \
+    'mkdir -p origin/sub && ( cd origin/sub && git init &&
+	echo file1 >file1 &&
+	git add file1 &&
+	git commit -m file1 ) &&
+    mkdir -p origin/main && ( cd origin/main && git init &&
+	git submodule add ../sub &&
+	git commit -m "add sub" ) &&
+    ( cd origin/sub &&
+	echo file1updated >file1 &&
+	git add file1 &&
+	git commit -m "file1 updated" ) &&
+    ( cd origin/main/sub && git pull ) &&
+    ( cd origin/main &&
+	git add sub &&
+	git commit -m "sub updated" )'
+
+test_expect_success 'setup: clone' \
+    'mkdir clone && ( cd clone &&
+	git clone --recursive "$base_path/origin/main")'
+
+rev1_hash_main=$(git --git-dir=origin/main/.git show --pretty=format:%h -q "HEAD~1")
+rev1_hash_sub=$(git --git-dir=origin/sub/.git show --pretty=format:%h -q "HEAD~1")
+
+test_expect_success 'checkout main' \
+    'mkdir default_checkout &&
+    (cd clone/main &&
+	git checkout --to "$base_path/default_checkout/main" "$rev1_hash_main")'
+
+test_expect_failure 'can see submodule diffs just after checkout' \
+    '(cd default_checkout/main && git diff --submodule master"^!" | grep "file1 updated")'
+
+test_expect_success 'checkout main and initialize independed clones' \
+    'mkdir fully_cloned_submodule &&
+    (cd clone/main &&
+	git checkout --to "$base_path/fully_cloned_submodule/main" "$rev1_hash_main") &&
+    (cd fully_cloned_submodule/main && git submodule update)'
+
+test_expect_success 'can see submodule diffs after independed cloning' \
+    '(cd fully_cloned_submodule/main && git diff --submodule master"^!" | grep "file1 updated")'
+
+test_done
diff --git a/t/t7502-commit.sh b/t/t7502-commit.sh
index 051489ea33..2e0d557243 100755
--- a/t/t7502-commit.sh
+++ b/t/t7502-commit.sh
@@ -370,7 +370,7 @@ exit 0
 EOF
 
 test_expect_success !AUTOIDENT 'do not fire editor when committer is bogus' '
-	>.git/result
+	>.git/result &&
 	>expect &&
 
 	echo >>negative &&
diff --git a/t/t7601-merge-pull-config.sh b/t/t7601-merge-pull-config.sh
index f768c900ab..c6c44ec570 100755
--- a/t/t7601-merge-pull-config.sh
+++ b/t/t7601-merge-pull-config.sh
@@ -45,6 +45,14 @@ test_expect_success 'fast-forward pull succeeds with "true" in pull.ff' '
 	test "$(git rev-parse HEAD)" = "$(git rev-parse c1)"
 '
 
+test_expect_success 'pull.ff=true overrides merge.ff=false' '
+	git reset --hard c0 &&
+	test_config merge.ff false &&
+	test_config pull.ff true &&
+	git pull . c1 &&
+	test "$(git rev-parse HEAD)" = "$(git rev-parse c1)"
+'
+
 test_expect_success 'fast-forward pull creates merge with "false" in pull.ff' '
 	git reset --hard c0 &&
 	test_config pull.ff false &&
diff --git a/t/t8003-blame-corner-cases.sh b/t/t8003-blame-corner-cases.sh
index 32895e5acb..16f1442c1e 100755
--- a/t/t8003-blame-corner-cases.sh
+++ b/t/t8003-blame-corner-cases.sh
@@ -191,12 +191,24 @@ test_expect_success 'indent of line numbers, ten lines' '
 	test $(grep -c "  " actual) = 9
 '
 
-test_expect_success 'blaming files with CRLF newlines' '
+test_expect_success 'setup file with CRLF newlines' '
 	git config core.autocrlf false &&
-	printf "testcase\r\n" >crlffile &&
+	printf "testcase\n" >crlffile &&
 	git add crlffile &&
 	git commit -m testcase &&
-	git -c core.autocrlf=input blame crlffile >actual &&
+	printf "testcase\r\n" >crlffile
+'
+
+test_expect_success 'blame file with CRLF core.autocrlf true' '
+	git config core.autocrlf true &&
+	git blame crlffile >actual &&
+	grep "A U Thor" actual
+'
+
+test_expect_success 'blame file with CRLF attributes text' '
+	git config core.autocrlf false &&
+	echo "crlffile text" >.gitattributes &&
+	git blame crlffile >actual &&
 	grep "A U Thor" actual
 '
 
diff --git a/t/t9402-git-cvsserver-refs.sh b/t/t9402-git-cvsserver-refs.sh
index 1e266effff..d00df08731 100755
--- a/t/t9402-git-cvsserver-refs.sh
+++ b/t/t9402-git-cvsserver-refs.sh
@@ -496,7 +496,7 @@ test_expect_success 'check [cvswork3] diff' '
 '
 
 test_expect_success 'merge early [cvswork3] b3 with b1' '
-	( cd gitwork3 && git merge "message" HEAD b1 ) &&
+	( cd gitwork3 && git merge -m "message" b1 ) &&
 	git fetch gitwork3 b3:b3 &&
 	git tag v3merged b3 &&
 	git push --tags gitcvs.git b3:b3
diff --git a/t/t9801-git-p4-branch.sh b/t/t9801-git-p4-branch.sh
index 2bf142d09c..0aafd03334 100755
--- a/t/t9801-git-p4-branch.sh
+++ b/t/t9801-git-p4-branch.sh
@@ -504,6 +504,112 @@ test_expect_success 'use-client-spec detect-branches skips files in branches' '
 	)
 '
 
+test_expect_success 'restart p4d' '
+	kill_p4d &&
+	start_p4d
+'
+
+#
+# 1: //depot/branch1/base/file1
+#    //depot/branch1/base/file2
+#    //depot/branch1/base/dir/sub_file1
+# 2: integrate //depot/branch1/base/... -> //depot/branch2/base/...
+# 3: //depot/branch1/base/file3
+# 4: //depot/branch1/base/file2 (edit)
+# 5: integrate //depot/branch1/base/... -> //depot/branch3/base/...
+#
+# Note: the client view removes the "base" folder from the workspace
+#       and moves sub_file1 one level up.
+test_expect_success 'add simple p4 branches with common base folder on each branch' '
+	(
+		cd "$cli" &&
+		client_view "//depot/branch1/base/... //client/branch1/..." \
+			    "//depot/branch1/base/dir/sub_file1 //client/branch1/sub_file1" \
+			    "//depot/branch2/base/... //client/branch2/..." \
+			    "//depot/branch3/base/... //client/branch3/..." &&
+		mkdir -p branch1 &&
+		cd branch1 &&
+		echo file1 >file1 &&
+		echo file2 >file2 &&
+		mkdir dir &&
+		echo sub_file1 >sub_file1 &&
+		p4 add file1 file2 sub_file1 &&
+		p4 submit -d "Create branch1" &&
+		p4 integrate //depot/branch1/base/... //depot/branch2/base/... &&
+		p4 submit -d "Integrate branch2 from branch1" &&
+		echo file3 >file3 &&
+		p4 add file3 &&
+		p4 submit -d "add file3 in branch1" &&
+		p4 open file2 &&
+		echo update >>file2 &&
+		p4 submit -d "update file2 in branch1" &&
+		p4 integrate //depot/branch1/base/... //depot/branch3/base/... &&
+		p4 submit -d "Integrate branch3 from branch1"
+	)
+'
+
+# Configure branches through git-config and clone them.
+# All files are tested to make sure branches were cloned correctly.
+# Finally, make an update to branch1 on P4 side to check if it is imported
+# correctly by git p4.
+# git p4 is expected to use the client view to also not include the common
+# "base" folder in the imported directory structure.
+test_expect_success 'git p4 clone simple branches with base folder on server side' '
+	test_create_repo "$git" &&
+	(
+		cd "$git" &&
+		git config git-p4.branchList branch1:branch2 &&
+		git config --add git-p4.branchList branch1:branch3 &&
+		git p4 clone --dest=. --use-client-spec  --detect-branches //depot@all &&
+		git log --all --graph --decorate --stat &&
+		git reset --hard p4/depot/branch1 &&
+		test -f file1 &&
+		test -f file2 &&
+		test -f file3 &&
+		test -f sub_file1 &&
+		grep update file2 &&
+		git reset --hard p4/depot/branch2 &&
+		test -f file1 &&
+		test -f file2 &&
+		test ! -f file3 &&
+		test -f sub_file1 &&
+		! grep update file2 &&
+		git reset --hard p4/depot/branch3 &&
+		test -f file1 &&
+		test -f file2 &&
+		test -f file3 &&
+		test -f sub_file1 &&
+		grep update file2 &&
+		cd "$cli" &&
+		cd branch1 &&
+		p4 edit file2 &&
+		echo file2_ >>file2 &&
+		p4 submit -d "update file2 in branch1" &&
+		cd "$git" &&
+		git reset --hard p4/depot/branch1 &&
+		git p4 rebase &&
+		grep file2_ file2
+	)
+'
+
+# Now update a file in one of the branches in git and submit to P4
+test_expect_success 'Update a file in git side and submit to P4 using client view' '
+	test_when_finished cleanup_git &&
+	(
+		cd "$git" &&
+		git reset --hard p4/depot/branch1 &&
+		echo "client spec" >> file1 &&
+		git add -u . &&
+		git commit -m "update file1 in branch1" &&
+		git config git-p4.skipSubmitEdit true &&
+		git p4 submit --verbose &&
+		cd "$cli" &&
+		p4 sync ... &&
+		cd branch1 &&
+		grep "client spec" file1
+	)
+'
+
 test_expect_success 'kill p4d' '
 	kill_p4d
 '
diff --git a/t/t9814-git-p4-rename.sh b/t/t9814-git-p4-rename.sh
index 99bb71b89c..c89992cf95 100755
--- a/t/t9814-git-p4-rename.sh
+++ b/t/t9814-git-p4-rename.sh
@@ -226,14 +226,9 @@ test_expect_success 'detect copies' '
 
 # See if configurables can be set, and in particular if the run.move.allow
 # variable exists, which allows admins to disable the "p4 move" command.
-test_expect_success 'p4 configure command and run.move.allow are available' '
-	p4 configure show run.move.allow >out ; retval=$? &&
-	test $retval = 0 &&
-	{
-		egrep ^run.move.allow: out &&
-		test_set_prereq P4D_HAVE_CONFIGURABLE_RUN_MOVE_ALLOW ||
-		true
-	} || true
+test_lazy_prereq P4D_HAVE_CONFIGURABLE_RUN_MOVE_ALLOW '
+	p4 configure show run.move.allow >out &&
+	egrep ^run.move.allow: out
 '
 
 # If move can be disabled, turn it off and test p4 move handling
diff --git a/t/t9816-git-p4-locked.sh b/t/t9816-git-p4-locked.sh
index e71e543343..d048bd33fa 100755
--- a/t/t9816-git-p4-locked.sh
+++ b/t/t9816-git-p4-locked.sh
@@ -35,13 +35,13 @@ test_expect_success 'edit with lock not taken' '
 	)
 '
 
-test_expect_failure 'add with lock not taken' '
+test_expect_success 'add with lock not taken' '
 	test_when_finished cleanup_git &&
 	git p4 clone --dest="$git" //depot &&
 	(
 		cd "$git" &&
 		echo line1 >>add-lock-not-taken &&
-		git add file2 &&
+		git add add-lock-not-taken &&
 		git commit -m "add add-lock-not-taken" &&
 		git config git-p4.skipSubmitEdit true &&
 		git p4 submit --verbose
@@ -107,7 +107,7 @@ test_expect_failure 'chmod with lock taken' '
 	)
 '
 
-test_expect_failure 'copy with lock taken' '
+test_expect_success 'copy with lock taken' '
 	lock_in_another_client &&
 	test_when_finished cleanup_git &&
 	test_when_finished "cd \"$cli\" && p4 revert file2 && rm -f file2" &&
@@ -130,8 +130,8 @@ test_expect_failure 'move with lock taken' '
 	git p4 clone --dest="$git" //depot &&
 	(
 		cd "$git" &&
-		git mv file1 file2 &&
-		git commit -m "mv file1 to file2" &&
+		git mv file1 file3 &&
+		git commit -m "mv file1 to file3" &&
 		git config git-p4.skipSubmitEdit true &&
 		git config git-p4.detectRenames true &&
 		git p4 submit --verbose
diff --git a/t/t9818-git-p4-block.sh b/t/t9818-git-p4-block.sh
new file mode 100755
index 0000000000..153b20afbd
--- /dev/null
+++ b/t/t9818-git-p4-block.sh
@@ -0,0 +1,64 @@
+#!/bin/sh
+
+test_description='git p4 fetching changes in multiple blocks'
+
+. ./lib-git-p4.sh
+
+test_expect_success 'start p4d' '
+	start_p4d
+'
+
+test_expect_success 'Create a repo with ~100 changes' '
+	(
+		cd "$cli" &&
+		>file.txt &&
+		p4 add file.txt &&
+		p4 submit -d "Add file.txt" &&
+		for i in $(test_seq 0 9)
+		do
+			>outer$i.txt &&
+			p4 add outer$i.txt &&
+			p4 submit -d "Adding outer$i.txt" &&
+			for j in $(test_seq 0 9)
+			do
+				p4 edit file.txt &&
+				echo $i$j >file.txt &&
+				p4 submit -d "Commit $i$j" || exit
+			done || exit
+		done
+	)
+'
+
+test_expect_success 'Clone the repo' '
+	git p4 clone --dest="$git" --changes-block-size=10 --verbose //depot@all
+'
+
+test_expect_success 'All files are present' '
+	echo file.txt >expected &&
+	test_write_lines outer0.txt outer1.txt outer2.txt outer3.txt outer4.txt >>expected &&
+	test_write_lines outer5.txt outer6.txt outer7.txt outer8.txt outer9.txt >>expected &&
+	ls "$git" >current &&
+	test_cmp expected current
+'
+
+test_expect_success 'file.txt is correct' '
+	echo 99 >expected &&
+	test_cmp expected "$git/file.txt"
+'
+
+test_expect_success 'Correct number of commits' '
+	(cd "$git" && git log --oneline) >log &&
+	test_line_count = 111 log
+'
+
+test_expect_success 'Previous version of file.txt is correct' '
+	(cd "$git" && git checkout HEAD^^) &&
+	echo 97 >expected &&
+	test_cmp expected "$git/file.txt"
+'
+
+test_expect_success 'kill p4d' '
+	kill_p4d
+'
+
+test_done
diff --git a/t/t9819-git-p4-case-folding.sh b/t/t9819-git-p4-case-folding.sh
new file mode 100755
index 0000000000..78f1d0f92d
--- /dev/null
+++ b/t/t9819-git-p4-case-folding.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+
+test_description='interaction with P4 case-folding'
+
+. ./lib-git-p4.sh
+
+test_expect_success 'start p4d with case folding enabled' '
+	start_p4d -C1
+'
+
+test_expect_success 'Create a repo, name is lowercase' '
+	(
+		client_view "//depot/... //client/..." &&
+		cd "$cli" &&
+		mkdir -p lc UC &&
+		>lc/file.txt && >UC/file.txt &&
+		p4 add lc/file.txt UC/file.txt &&
+		p4 submit -d "Add initial lc and UC repos"
+	)
+'
+
+test_expect_success 'Check p4 is in case-folding mode' '
+	(
+		cd "$cli" &&
+		>lc/FILE.TXT &&
+		p4 add lc/FILE.TXT &&
+		test_must_fail p4 submit -d "Cannot add file differing only in case" lc/FILE.TXT
+	)
+'
+
+# Check we created the repo properly
+test_expect_success 'Clone lc repo using lc name' '
+	git p4 clone //depot/lc/... &&
+	test_path_is_file lc/file.txt &&
+	git p4 clone //depot/UC/... &&
+	test_path_is_file UC/file.txt
+'
+
+# The clone should fail, since there is no repo called LC, but because
+# we have case-insensitive p4d enabled, it appears to go ahead and work,
+# but leaves an empty git repo in place.
+test_expect_failure 'Clone lc repo using uc name' '
+	test_must_fail git p4 clone //depot/LC/...
+'
+
+test_expect_failure 'Clone UC repo with lc name' '
+	test_must_fail git p4 clone //depot/uc/...
+'
+
+test_expect_success 'kill p4d' '
+	kill_p4d
+'
+
+test_done
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 4a14a5892e..2ba62fbc17 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -370,6 +370,40 @@ test_expect_success '__git_remotes - list remotes from $GIT_DIR/remotes and from
 	test_cmp expect actual
 '
 
+test_expect_success '__git_get_config_variables' '
+	cat >expect <<-EOF &&
+	name-1
+	name-2
+	EOF
+	test_config interesting.name-1 good &&
+	test_config interesting.name-2 good &&
+	test_config subsection.interesting.name-3 bad &&
+	__git_get_config_variables interesting >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '__git_pretty_aliases' '
+	cat >expect <<-EOF &&
+	author
+	hash
+	EOF
+	test_config pretty.author "%an %ae" &&
+	test_config pretty.hash %H &&
+	__git_pretty_aliases >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '__git_aliases' '
+	cat >expect <<-EOF &&
+	ci
+	co
+	EOF
+	test_config alias.ci commit &&
+	test_config alias.co checkout &&
+	__git_aliases >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'basic' '
 	run_completion "git " &&
 	# built-in
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 0698ce7908..e8d3c0fdbc 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -348,11 +348,18 @@ test_declared_prereq () {
 	return 1
 }
 
+test_verify_prereq () {
+	test -z "$test_prereq" ||
+	expr >/dev/null "$test_prereq" : '[A-Z0-9_,!]*$' ||
+	error "bug in the test script: '$test_prereq' does not look like a prereq"
+}
+
 test_expect_failure () {
 	test_start_
 	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
 	test "$#" = 2 ||
 	error "bug in the test script: not 2 or 3 parameters to test-expect-failure"
+	test_verify_prereq
 	export test_prereq
 	if ! test_skip "$@"
 	then
@@ -372,6 +379,7 @@ test_expect_success () {
 	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
 	test "$#" = 2 ||
 	error "bug in the test script: not 2 or 3 parameters to test-expect-success"
+	test_verify_prereq
 	export test_prereq
 	if ! test_skip "$@"
 	then
@@ -400,6 +408,7 @@ test_external () {
 	error >&5 "bug in the test script: not 3 or 4 parameters to test_external"
 	descr="$1"
 	shift
+	test_verify_prereq
 	export test_prereq
 	if ! test_skip "$descr" "$@"
 	then
@@ -478,7 +487,7 @@ test_external_without_stderr () {
 test_path_is_file () {
 	if ! test -f "$1"
 	then
-		echo "File $1 doesn't exist. $*"
+		echo "File $1 doesn't exist. $2"
 		false
 	fi
 }
@@ -486,7 +495,7 @@ test_path_is_file () {
 test_path_is_dir () {
 	if ! test -d "$1"
 	then
-		echo "Directory $1 doesn't exist. $*"
+		echo "Directory $1 doesn't exist. $2"
 		false
 	fi
 }
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 4ea99a209d..39da9c2d99 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -529,7 +529,7 @@ test_run_ () {
 	test_cleanup=:
 	expecting_failure=$2
 
-	if test "${GIT_TEST_CHAIN_LINT:-0}" != 0; then
+	if test "${GIT_TEST_CHAIN_LINT:-1}" != 0; then
 		# 117 is magic because it is unlikely to match the exit
 		# code of other programs
 		test_eval_ "(exit 117) && $1"
diff --git a/templates/hooks--applypatch-msg.sample b/templates/hooks--applypatch-msg.sample
index 8b2a2fe84f..a5d7b84a67 100755
--- a/templates/hooks--applypatch-msg.sample
+++ b/templates/hooks--applypatch-msg.sample
@@ -10,6 +10,6 @@
 # To enable this hook, rename this file to "applypatch-msg".
 
 . git-sh-setup
-test -x "$GIT_DIR/hooks/commit-msg" &&
-	exec "$GIT_DIR/hooks/commit-msg" ${1+"$@"}
+commitmsg="$(git rev-parse --git-path hooks/commit-msg)"
+test -x "$commitmsg" && exec "$commitmsg" ${1+"$@"}
 :
diff --git a/templates/hooks--pre-applypatch.sample b/templates/hooks--pre-applypatch.sample
index b1f187c2e9..4142082bcb 100755
--- a/templates/hooks--pre-applypatch.sample
+++ b/templates/hooks--pre-applypatch.sample
@@ -9,6 +9,6 @@
 # To enable this hook, rename this file to "pre-applypatch".
 
 . git-sh-setup
-test -x "$GIT_DIR/hooks/pre-commit" &&
-	exec "$GIT_DIR/hooks/pre-commit" ${1+"$@"}
+precommit="$(git rev-parse --git-path hooks/pre-commit)"
+test -x "$precommit" && exec "$precommit" ${1+"$@"}
 :
diff --git a/test-dump-untracked-cache.c b/test-dump-untracked-cache.c
new file mode 100644
index 0000000000..25d855d98b
--- /dev/null
+++ b/test-dump-untracked-cache.c
@@ -0,0 +1,62 @@
+#include "cache.h"
+#include "dir.h"
+
+static int compare_untracked(const void *a_, const void *b_)
+{
+	const char *const *a = a_;
+	const char *const *b = b_;
+	return strcmp(*a, *b);
+}
+
+static int compare_dir(const void *a_, const void *b_)
+{
+	const struct untracked_cache_dir *const *a = a_;
+	const struct untracked_cache_dir *const *b = b_;
+	return strcmp((*a)->name, (*b)->name);
+}
+
+static void dump(struct untracked_cache_dir *ucd, struct strbuf *base)
+{
+	int i, len;
+	qsort(ucd->untracked, ucd->untracked_nr, sizeof(*ucd->untracked),
+	      compare_untracked);
+	qsort(ucd->dirs, ucd->dirs_nr, sizeof(*ucd->dirs),
+	      compare_dir);
+	len = base->len;
+	strbuf_addf(base, "%s/", ucd->name);
+	printf("%s %s", base->buf,
+	       sha1_to_hex(ucd->exclude_sha1));
+	if (ucd->recurse)
+		fputs(" recurse", stdout);
+	if (ucd->check_only)
+		fputs(" check_only", stdout);
+	if (ucd->valid)
+		fputs(" valid", stdout);
+	printf("\n");
+	for (i = 0; i < ucd->untracked_nr; i++)
+		printf("%s\n", ucd->untracked[i]);
+	for (i = 0; i < ucd->dirs_nr; i++)
+		dump(ucd->dirs[i], base);
+	strbuf_setlen(base, len);
+}
+
+int main(int ac, char **av)
+{
+	struct untracked_cache *uc;
+	struct strbuf base = STRBUF_INIT;
+	setup_git_directory();
+	if (read_cache() < 0)
+		die("unable to read index file");
+	uc = the_index.untracked;
+	if (!uc) {
+		printf("no untracked cache\n");
+		return 0;
+	}
+	printf("info/exclude %s\n", sha1_to_hex(uc->ss_info_exclude.sha1));
+	printf("core.excludesfile %s\n", sha1_to_hex(uc->ss_excludes_file.sha1));
+	printf("exclude_per_dir %s\n", uc->exclude_per_dir);
+	printf("flags %08x\n", uc->dir_flags);
+	if (uc->root)
+		dump(uc->root, &base);
+	return 0;
+}
diff --git a/trace.c b/trace.c
index 1dc5c7c912..3c3bd8fc98 100644
--- a/trace.c
+++ b/trace.c
@@ -310,6 +310,7 @@ void trace_repo_setup(const char *prefix)
 		prefix = "(null)";
 
 	trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
+	trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 	trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 	trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 	trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
diff --git a/transport.c b/transport.c
index eca9b8c817..f080e93dcd 100644
--- a/transport.c
+++ b/transport.c
@@ -283,7 +283,6 @@ static int write_one_ref(const char *name, const unsigned char *sha1,
 {
 	struct strbuf *buf = data;
 	int len = buf->len;
-	FILE *f;
 
 	/* when called via for_each_ref(), flags is non-zero */
 	if (flags && !starts_with(name, "refs/heads/") &&
@@ -292,10 +291,9 @@ static int write_one_ref(const char *name, const unsigned char *sha1,
 
 	strbuf_addstr(buf, name);
 	if (safe_create_leading_directories(buf->buf) ||
-			!(f = fopen(buf->buf, "w")) ||
-			fprintf(f, "%s\n", sha1_to_hex(sha1)) < 0 ||
-			fclose(f))
-		return error("problems writing temporary file %s", buf->buf);
+	    write_file(buf->buf, 0, "%s\n", sha1_to_hex(sha1)))
+		return error("problems writing temporary file %s: %s",
+			     buf->buf, strerror(errno));
 	strbuf_setlen(buf, len);
 	return 0;
 }
diff --git a/tree-diff.c b/tree-diff.c
index e7b378c8b2..290a1da4ce 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -64,7 +64,7 @@ static int emit_diff_first_parent_only(struct diff_options *opt, struct combine_
 {
 	struct combine_diff_parent *p0 = &p->parent[0];
 	if (p->mode && p0->mode) {
-		opt->change(opt, p0->mode, p->mode, p0->sha1, p->sha1,
+		opt->change(opt, p0->mode, p->mode, p0->oid.hash, p->oid.hash,
 			1, 1, p->path, 0, 0);
 	}
 	else {
@@ -74,11 +74,11 @@ static int emit_diff_first_parent_only(struct diff_options *opt, struct combine_
 
 		if (p->mode) {
 			addremove = '+';
-			sha1 = p->sha1;
+			sha1 = p->oid.hash;
 			mode = p->mode;
 		} else {
 			addremove = '-';
-			sha1 = p0->sha1;
+			sha1 = p0->oid.hash;
 			mode = p0->mode;
 		}
 
@@ -151,7 +151,7 @@ static struct combine_diff_path *path_appendnew(struct combine_diff_path *last,
 	memcpy(p->path + base->len, path, pathlen);
 	p->path[len] = 0;
 	p->mode = mode;
-	hashcpy(p->sha1, sha1 ? sha1 : null_sha1);
+	hashcpy(p->oid.hash, sha1 ? sha1 : null_sha1);
 
 	return p;
 }
@@ -238,7 +238,7 @@ static struct combine_diff_path *emit_path(struct combine_diff_path *p,
 			}
 
 			p->parent[i].mode = mode_i;
-			hashcpy(p->parent[i].sha1, sha1_i ? sha1_i : null_sha1);
+			hashcpy(p->parent[i].oid.hash, sha1_i ? sha1_i : null_sha1);
 		}
 
 		keep = 1;
diff --git a/tree-walk.c b/tree-walk.c
index 5dd9a71804..6dccd2d5dd 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -415,6 +415,12 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 	return error;
 }
 
+struct dir_state {
+	void *tree;
+	unsigned long size;
+	unsigned char sha1[20];
+};
+
 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
 {
 	int namelen = strlen(name);
@@ -478,6 +484,206 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 	return retval;
 }
 
+/*
+ * This is Linux's built-in max for the number of symlinks to follow.
+ * That limit, of course, does not affect git, but it's a reasonable
+ * choice.
+ */
+#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
+
+/**
+ * Find a tree entry by following symlinks in tree_sha (which is
+ * assumed to be the root of the repository).  In the event that a
+ * symlink points outside the repository (e.g. a link to /foo or a
+ * root-level link to ../foo), the portion of the link which is
+ * outside the repository will be returned in result_path, and *mode
+ * will be set to 0.  It is assumed that result_path is uninitialized.
+ * If there are no symlinks, or the end result of the symlink chain
+ * points to an object inside the repository, result will be filled in
+ * with the sha1 of the found object, and *mode will hold the mode of
+ * the object.
+ *
+ * See the code for enum follow_symlink_result for a description of
+ * the return values.
+ */
+enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_sha1, const char *name, unsigned char *result, struct strbuf *result_path, unsigned *mode)
+{
+	int retval = MISSING_OBJECT;
+	struct dir_state *parents = NULL;
+	size_t parents_alloc = 0;
+	ssize_t parents_nr = 0;
+	unsigned char current_tree_sha1[20];
+	struct strbuf namebuf = STRBUF_INIT;
+	struct tree_desc t;
+	int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
+	int i;
+
+	init_tree_desc(&t, NULL, 0UL);
+	strbuf_init(result_path, 0);
+	strbuf_addstr(&namebuf, name);
+	hashcpy(current_tree_sha1, tree_sha1);
+
+	while (1) {
+		int find_result;
+		char *first_slash;
+		char *remainder = NULL;
+
+		if (!t.buffer) {
+			void *tree;
+			unsigned char root[20];
+			unsigned long size;
+			tree = read_object_with_reference(current_tree_sha1,
+							  tree_type, &size,
+							  root);
+			if (!tree)
+				goto done;
+
+			ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
+			parents[parents_nr].tree = tree;
+			parents[parents_nr].size = size;
+			hashcpy(parents[parents_nr].sha1, root);
+			parents_nr++;
+
+			if (namebuf.buf[0] == '\0') {
+				hashcpy(result, root);
+				retval = FOUND;
+				goto done;
+			}
+
+			if (!size)
+				goto done;
+
+			/* descend */
+			init_tree_desc(&t, tree, size);
+		}
+
+		/* Handle symlinks to e.g. a//b by removing leading slashes */
+		while (namebuf.buf[0] == '/') {
+			strbuf_remove(&namebuf, 0, 1);
+		}
+
+		/* Split namebuf into a first component and a remainder */
+		if ((first_slash = strchr(namebuf.buf, '/'))) {
+			*first_slash = 0;
+			remainder = first_slash + 1;
+		}
+
+		if (!strcmp(namebuf.buf, "..")) {
+			struct dir_state *parent;
+			/*
+			 * We could end up with .. in the namebuf if it
+			 * appears in a symlink.
+			 */
+
+			if (parents_nr == 1) {
+				if (remainder)
+					*first_slash = '/';
+				strbuf_add(result_path, namebuf.buf,
+					   namebuf.len);
+				*mode = 0;
+				retval = FOUND;
+				goto done;
+			}
+			parent = &parents[parents_nr - 1];
+			free(parent->tree);
+			parents_nr--;
+			parent = &parents[parents_nr - 1];
+			init_tree_desc(&t, parent->tree, parent->size);
+			strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
+			continue;
+		}
+
+		/* We could end up here via a symlink to dir/.. */
+		if (namebuf.buf[0] == '\0') {
+			hashcpy(result, parents[parents_nr - 1].sha1);
+			retval = FOUND;
+			goto done;
+		}
+
+		/* Look up the first (or only) path component in the tree. */
+		find_result = find_tree_entry(&t, namebuf.buf,
+					      current_tree_sha1, mode);
+		if (find_result) {
+			goto done;
+		}
+
+		if (S_ISDIR(*mode)) {
+			if (!remainder) {
+				hashcpy(result, current_tree_sha1);
+				retval = FOUND;
+				goto done;
+			}
+			/* Descend the tree */
+			t.buffer = NULL;
+			strbuf_remove(&namebuf, 0,
+				      1 + first_slash - namebuf.buf);
+		} else if (S_ISREG(*mode)) {
+			if (!remainder) {
+				hashcpy(result, current_tree_sha1);
+				retval = FOUND;
+			} else {
+				retval = NOT_DIR;
+			}
+			goto done;
+		} else if (S_ISLNK(*mode)) {
+			/* Follow a symlink */
+			unsigned long link_len;
+			size_t len;
+			char *contents, *contents_start;
+			struct dir_state *parent;
+			enum object_type type;
+
+			if (follows_remaining-- == 0) {
+				/* Too many symlinks followed */
+				retval = SYMLINK_LOOP;
+				goto done;
+			}
+
+			/*
+			 * At this point, we have followed at a least
+			 * one symlink, so on error we need to report this.
+			 */
+			retval = DANGLING_SYMLINK;
+
+			contents = read_sha1_file(current_tree_sha1, &type,
+						  &link_len);
+
+			if (!contents)
+				goto done;
+
+			if (contents[0] == '/') {
+				strbuf_addstr(result_path, contents);
+				free(contents);
+				*mode = 0;
+				retval = FOUND;
+				goto done;
+			}
+
+			if (remainder)
+				len = first_slash - namebuf.buf;
+			else
+				len = namebuf.len;
+
+			contents_start = contents;
+
+			parent = &parents[parents_nr - 1];
+			init_tree_desc(&t, parent->tree, parent->size);
+			strbuf_splice(&namebuf, 0, len,
+				      contents_start, link_len);
+			if (remainder)
+				namebuf.buf[link_len] = '/';
+			free(contents);
+		}
+	}
+done:
+	for (i = 0; i < parents_nr; i++)
+		free(parents[i].tree);
+	free(parents);
+
+	strbuf_release(&namebuf);
+	return retval;
+}
+
 static int match_entry(const struct pathspec_item *item,
 		       const struct name_entry *entry, int pathlen,
 		       const char *match, int matchlen,
diff --git a/tree-walk.h b/tree-walk.h
index ae7fb3a824..3b2f7bf17d 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -40,6 +40,24 @@ struct traverse_info;
 typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);
 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info);
 
+enum follow_symlinks_result {
+	FOUND = 0, /* This includes out-of-tree links */
+	MISSING_OBJECT = -1, /* The initial symlink is missing */
+	DANGLING_SYMLINK = -2, /*
+				* The initial symlink is there, but
+				* (transitively) points to a missing
+				* in-tree file
+				*/
+	SYMLINK_LOOP = -3,
+	NOT_DIR = -4, /*
+		       * Somewhere along the symlink chain, a path is
+		       * requested which contains a file as a
+		       * non-final element.
+		       */
+};
+
+enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_sha1, const char *name, unsigned char *result, struct strbuf *result_path, unsigned *mode);
+
 struct traverse_info {
 	struct traverse_info *prev;
 	struct name_entry name;
diff --git a/unpack-trees.c b/unpack-trees.c
index be84ba2607..2927660d92 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -9,6 +9,7 @@
 #include "refs.h"
 #include "attr.h"
 #include "split-index.h"
+#include "dir.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -1259,8 +1260,10 @@ static int verify_uptodate_sparse(const struct cache_entry *ce,
 static void invalidate_ce_path(const struct cache_entry *ce,
 			       struct unpack_trees_options *o)
 {
-	if (ce)
-		cache_tree_invalidate_path(o->src_index, ce->name);
+	if (!ce)
+		return;
+	cache_tree_invalidate_path(o->src_index, ce->name);
+	untracked_cache_invalidate_path(o->src_index, ce->name);
 }
 
 /*
diff --git a/upload-pack.c b/upload-pack.c
index 5cb4ac4ccc..640eae1bbe 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -78,7 +78,7 @@ static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 {
 	FILE *fp = cb_data;
 	if (graft->nr_parent == -1)
-		fprintf(fp, "--shallow %s\n", sha1_to_hex(graft->sha1));
+		fprintf(fp, "--shallow %s\n", oid_to_hex(&graft->oid));
 	return 0;
 }
 
diff --git a/utf8.c b/utf8.c
index 520fbb4994..28e6d76a42 100644
--- a/utf8.c
+++ b/utf8.c
@@ -633,3 +633,14 @@ int is_hfs_dotgit(const char *path)
 
 	return 1;
 }
+
+const char utf8_bom[] = "\357\273\277";
+
+int skip_utf8_bom(char **text, size_t len)
+{
+	if (len < strlen(utf8_bom) ||
+	    memcmp(*text, utf8_bom, strlen(utf8_bom)))
+		return 0;
+	*text += strlen(utf8_bom);
+	return 1;
+}
diff --git a/utf8.h b/utf8.h
index e4d9183c5f..e7b2aa4168 100644
--- a/utf8.h
+++ b/utf8.h
@@ -13,6 +13,9 @@ int same_encoding(const char *, const char *);
 __attribute__((format (printf, 2, 3)))
 int utf8_fprintf(FILE *, const char *, ...);
 
+extern const char utf8_bom[];
+extern int skip_utf8_bom(char **, size_t);
+
 void strbuf_add_wrapped_text(struct strbuf *buf,
 		const char *text, int indent, int indent2, int width);
 void strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
diff --git a/wrapper.c b/wrapper.c
index d5a6cef2be..c1a663fd59 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -564,3 +564,34 @@ char *xgetcwd(void)
 		die_errno(_("unable to get current working directory"));
 	return strbuf_detach(&sb, NULL);
 }
+
+int write_file(const char *path, int fatal, const char *fmt, ...)
+{
+	struct strbuf sb = STRBUF_INIT;
+	va_list params;
+	int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
+	if (fd < 0) {
+		if (fatal)
+			die_errno(_("could not open %s for writing"), path);
+		return -1;
+	}
+	va_start(params, fmt);
+	strbuf_vaddf(&sb, fmt, params);
+	va_end(params);
+	if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
+		int err = errno;
+		close(fd);
+		strbuf_release(&sb);
+		errno = err;
+		if (fatal)
+			die_errno(_("could not write to %s"), path);
+		return -1;
+	}
+	strbuf_release(&sb);
+	if (close(fd)) {
+		if (fatal)
+			die_errno(_("could not close %s"), path);
+		return -1;
+	}
+	return 0;
+}
diff --git a/wt-status.c b/wt-status.c
index 38cb165f12..33452f169d 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -585,6 +585,8 @@ static void wt_status_collect_untracked(struct wt_status *s)
 			DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;
 	if (s->show_ignored_files)
 		dir.flags |= DIR_SHOW_IGNORED_TOO;
+	else
+		dir.untracked = the_index.untracked;
 	setup_standard_excludes(&dir);
 
 	fill_directory(&dir, &s->pathspec);