Git 2.11 Release Notes
======================
+Backward compatibility notes.
+
+ * An empty string used as a pathspec element has always meant
+ 'everything matches', but it is too easy to write a script that
+ finds a path to remove in $path and run 'git rm "$paht"' by
+ mistake (when the user meant to give "$path"), which ends up
+ removing everything. This release starts warning about the
+ use of an empty string that is used for 'everything matches' and
+ asks users to use a more explicit '.' for that instead.
+
+ The hope is that existing users will not mind this change, and
+ eventually the warning can be turned into a hard error, upgrading
+ the deprecation into removal of this (mis)feature.
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+ has been deprecated for quite some time, and will be removed in the
+ next release (not this one).
+
+ * The default abbreviation length, which has historically been 7, now
+ scales as the repository grows, using the approximate number of
+ objects in the repository and a bit of math around the birthday
+ paradox. The logic suggests to use 12 hexdigits for the Linux
+ kernel, and 9 to 10 for Git itself.
+
+
Updates since v2.10
-------------------
UI, Workflows & Features
+ * Comes with new version of git-gui, now at its 0.21.0 tag.
+
* "git format-patch --cover-letter HEAD^" to format a single patch
with a separate cover letter now numbers the output as [PATCH 0/1]
and [PATCH 1/1] by default.
which was not intuitive, given that "git nosuchcommand" said "git:
'nosuchcommand' is not a git command".
- * "git clone --resurse-submodules --reference $path $URL" is a way to
+ * "git clone --recurse-submodules --reference $path $URL" is a way to
reduce network transfer cost by borrowing objects in an existing
$path repository when cloning the superproject from $URL; it
- learned to also peek into $path for presense of corresponding
+ learned to also peek into $path for presence of corresponding
repositories of submodules and borrow objects from there when able.
+ * The "git diff --submodule={short,log}" mechanism has been enhanced
+ to allow "--submodule=diff" to show the patch between the submodule
+ commits bound to the superproject.
+
+ * Even though "git hash-objects", which is a tool to take an
+ on-filesystem data stream and put it into the Git object store,
+ can perform "outside-world-to-Git" conversions (e.g.
+ end-of-line conversions and application of the clean-filter), and
+ it has had this feature on by default from very early days, its reverse
+ operation "git cat-file", which takes an object from the Git object
+ store and externalizes it for consumption by the outside world,
+ lacked an equivalent mechanism to run the "Git-to-outside-world"
+ conversion. The command learned the "--filters" option to do so.
+
+ * Output from "git diff" can be made easier to read by intelligently selecting
+ which lines are common and which lines are added/deleted
+ when the lines before and after the changed section
+ are the same. A command line option (--indent-heuristic) and a
+ configuration variable (diff.indentHeuristic) are added to help with the
+ experiment to find good heuristics.
+
+ * In some projects, it is common to use "[RFC PATCH]" as the subject
+ prefix for a patch meant for discussion rather than application. A
+ new format-patch option "--rfc" is a short-hand for "--subject-prefix=RFC PATCH"
+ to help the participants of such projects.
+
+ * "git add --chmod={+,-}x <pathspec>" only changed the
+ executable bit for paths that are either new or modified. This has
+ been corrected to change the executable bit for all paths that match
+ the given pathspec.
+
+ * When "git format-patch --stdout" output is placed as an in-body
+ header and it uses RFC2822 header folding, "git am" fails to
+ put the header line back into a single logical line. The
+ underlying "git mailinfo" was taught to handle this properly.
+
+ * "gitweb" can spawn "highlight" to show blob contents with
+ (programming) language-specific syntax highlighting, but only
+ when the language is known. "highlight" can however be told
+ to guess the language itself by giving it "--force" option, which
+ has been enabled.
+
+ * "git gui" l10n to Portuguese.
+
+ * When given an abbreviated object name that is not (or more
+ realistically, "no longer") unique, we gave a fatal error
+ "ambiguous argument". This error is now accompanied by a hint that
+ lists the objects beginning with the given prefix. During the
+ course of development of this new feature, numerous minor bugs were
+ uncovered and corrected, the most notable one of which is that we
+ gave "short SHA1 xxxx is ambiguous." twice without good reason.
+
+ * "git log rev^..rev" is an often-used revision range specification
+ to show what was done on a side branch merged at rev. This has
+ gained a short-hand "rev^-1". In general "rev^-$n" is the same as
+ "^rev^$n rev", i.e. what has happened on other branches while the
+ history leading to nth parent was looking the other way.
+
+ * In recent versions of cURL, GSSAPI credential delegation is
+ disabled by default due to CVE-2011-2192; introduce a http.delegation
+ configuration variable to selectively allow enabling this.
+ (merge 26a7b23429 ps/http-gssapi-cred-delegation later to maint).
+
+ * "git mergetool" learned to honor "-O<orderfile>" to control the
+ order of paths to present to the end user.
+
+ * "git diff/log --ws-error-highlight=<kind>" lacked the corresponding
+ configuration variable (diff.wsErrorHighlight) to set it by default.
+
+ * "git ls-files" learned the "--recurse-submodules" option
+ to get a listing of tracked files across submodules (i.e. this
+ only works with the "--cached" option, not for listing untracked or
+ ignored files). This would be a useful tool to sit on the upstream
+ side of a pipe that is read with xargs to work on all working tree
+ files from the top-level superproject.
+
+ * A new credential helper that talks via "libsecret" with
+ implementations of XDG Secret Service API has been added to
+ contrib/credential/.
+
+ * The GPG verification status shown by the "%G?" pretty format specifier
+ was not rich enough to differentiate a signature made by an expired
+ key, a signature made by a revoked key, etc. New output letters
+ have been assigned to express them.
+
+ * In addition to purely abbreviated commit object names, "gitweb"
+ learned to turn "git describe" output (e.g. v2.9.3-599-g2376d31787)
+ into clickable links in its output.
+
+ * "git commit" created an empty commit when invoked with an index
+ consisting solely of intend-to-add paths (added with "git add -N").
+ It now requires the "--allow-empty" option to create such a commit.
+ The same logic prevented "git status" from showing such paths as "new files" in the
+ "Changes not staged for commit" section.
+
+ * The smudge/clean filter API spawns an external process
+ to filter the contents of each path that has a filter defined. A
+ new type of "process" filter API has been added to allow the first
+ request to run the filter for a path to spawn a single process, and
+ all filtering is served by this single process for multiple
+ paths, reducing the process creation overhead.
+
+ * The user always has to say "stash@{$N}" when naming a single
+ element in the default location of the stash, i.e. reflogs in
+ refs/stash. The "git stash" command learned to accept "git stash
+ apply 4" as a short-hand for "git stash apply stash@{4}".
+
Performance, Internal Implementation, Development Support etc.
further be used to teach git-prompt (in contrib/) to make fewer
calls to git.
+ * Extract a small helper out of the function that reads the authors
+ script file "git am" internally uses.
+ (merge a77598e jc/am-read-author-file later to maint).
+
+ * Lift calls to exit(2) and die() higher in the callchain in
+ sequencer.c files so that more helper functions in it can be used
+ by callers that want to handle error conditions themselves.
+
+ * "git am" has been taught to make an internal call to "git apply"'s
+ innards without spawning the latter as a separate process.
+
+ * The ref-store abstraction was introduced to the refs API so that we
+ can plug in different backends to store references.
+
+ * The "unsigned char sha1[20]" to "struct object_id" conversion
+ continues. Notable changes in this round includes that ce->sha1,
+ i.e. the object name recorded in the cache_entry, turns into an
+ object_id.
+
+ * JGit can show a fake ref "capabilities^{}" to "git fetch" when it
+ does not advertise any refs, but "git fetch" was not prepared to
+ see such an advertisement. When the other side disconnects without
+ giving any ref advertisement, we used to say "there may not be a
+ repository at that URL", but we may have seen other advertisements
+ like "shallow" and ".have" in which case we definitely know that a
+ repository is there. The code to detect this case has also been
+ updated.
+
+ * Some codepaths in "git pack-objects" were not ready to use an
+ existing pack bitmap; now they are and as a result they have
+ become faster.
+
+ * The codepath in "git fsck" to detect malformed tree objects has
+ been updated not to die but keep going after detecting them.
+
+ * We call "qsort(array, nelem, sizeof(array[0]), fn)", and most of
+ the time third parameter is redundant. A new QSORT() macro lets us
+ omit it.
+
+ * "git pack-objects" in a repository with many packfiles used to
+ spend a lot of time looking for/at objects in them; the accesses to
+ the packfiles are now optimized by checking the most-recently-used
+ packfile first.
+ (merge c9af708b1a jk/pack-objects-optim-mru later to maint).
+
+ * Codepaths involved in interacting alternate object stores have
+ been cleaned up.
+
+ * In order for the receiving end of "git push" to inspect the
+ received history and decide to reject the push, the objects sent
+ from the sending end need to be made available to the hook and
+ the mechanism for the connectivity check, and this was done
+ traditionally by storing the objects in the receiving repository
+ and letting "git gc" expire them. Instead, store the newly
+ received objects in a temporary area, and make them available by
+ reusing the alternate object store mechanism to them only while we
+ decide if we accept the check, and once we decide, either migrate
+ them to the repository or purge them immediately.
+
+ * The require_clean_work_tree() helper was recreated in C when "git
+ pull" was rewritten from shell; the helper is now made available to
+ other callers in preparation for upcoming "rebase -i" work.
+
+ * "git upload-pack" had its code cleaned-up and performance improved
+ by reducing use of timestamp-ordered commit-list, which was
+ replaced with a priority queue.
+
+ * "git diff --no-index" codepath has been updated not to try to peek
+ into a .git/ directory that happens to be under the current
+ directory, when we know we are operating outside any repository.
+
+ * Update of the sequencer codebase to make it reusable to reimplement
+ "rebase -i" continues.
+
+ * Git generally does not explicitly close file descriptors that were
+ open in the parent process when spawning a child process, but most
+ of the time the child does not want to access them. As Windows does
+ not allow removing or renaming a file that has a file descriptor
+ open, a slow-to-exit child can even break the parent process by
+ holding onto them. Use O_CLOEXEC flag to open files in various
+ codepaths.
+
+ * Update "interpret-trailers" machinery and teach it that people in
+ the real world write all sorts of cruft in the "trailer" that was
+ originally designed to have the neat-o "Mail-Header: like thing"
+ and nothing else.
+
Also contains various documentation updates and code clean-ups.
* Clarify various ways to specify the "revision ranges" in the
documentation.
- (merge a117be4 po/range-doc later to maint).
* "diff-highlight" script (in contrib/) learned to work better with
"git log -p --graph" output.
- (merge 3dbfe2b bh/diff-highlight-graph later to maint).
+
+ * The test framework left the number of tests and success/failure
+ count in the t/test-results directory, keyed by the name of the
+ test script plus the process ID. The latter however turned out not
+ to serve any useful purpose. The process ID part of the filename
+ has been removed.
+
+ * Having a submodule whose ".git" repository is somehow corrupt
+ caused a few commands that recurse into submodules to loop forever.
+
+ * "git symbolic-ref -d HEAD" happily removes the symbolic ref, but
+ the resulting repository becomes an invalid one. Teach the command
+ to forbid removal of HEAD.
+
+ * A test spawned a short-lived background process, which sometimes
+ prevented the test directory from getting removed at the end of the
+ script on some platforms.
+
+ * Update a few tests that used to use GIT_CURL_VERBOSE to use the
+ newer GIT_TRACE_CURL.
+
+ * "git pack-objects --include-tag" was taught that when we know that
+ we are sending an object C, we want a tag B that directly points at
+ C but also a tag A that points at the tag B. We used to miss the
+ intermediate tag B in some cases.
+
+ * Update Japanese translation for "git-gui".
+
+ * "git fetch http::/site/path" did not die correctly and segfaulted
+ instead.
+
+ * "git commit-tree" stopped reading commit.gpgsign configuration
+ variable that was meant for Porcelain "git commit" in Git 2.9; we
+ forgot to update "git gui" to look at the configuration to match
+ this change.
+
+ * "git add --chmod={+,-}x" added recently lacked documentation, which has
+ been corrected.
+
+ * "git log --cherry-pick" used to include merge commits as candidates
+ to be matched up with other commits, resulting a lot of wasted time.
+ The patch-id generation logic has been updated to ignore merges and
+ avoid the wastage.
+
+ * The http transport (with curl-multi option, which is the default
+ these days) failed to remove curl-easy handle from a curlm session,
+ which led to unnecessary API failures.
+
+ * There were numerous corner cases in which the configuration files
+ are read and used or not read at all depending on the directory a
+ Git command was run, leading to inconsistent behaviour. The code
+ to set-up repository access at the beginning of a Git process has
+ been updated to fix them.
+ (merge 4d0efa1 jk/setup-sequence-update later to maint).
+
+ * "git diff -W" output needs to extend the context backward to
+ include the header line of the current function and also forward to
+ include the body of the entire current function up to the header
+ line of the next one. This process may have to merge two adjacent
+ hunks, but the code forgot to do so in some cases.
+
+ * Performance tests done via "t/perf" did not use the right
+ build configuration if the user relied on autoconf generated
+ configuration.
+
+ * "git format-patch --base=..." feature that was recently added
+ showed the base commit information after the "-- " e-mail signature
+ line, which turned out to be inconvenient. The base information
+ has been moved above the signature line.
+
+ * More i18n.
+
+ * Even when "git pull --rebase=preserve" (and the underlying "git
+ rebase --preserve") can complete without creating any new commits
+ (i.e. fast-forwards), it still insisted on having usable ident
+ information (read: user.email is set correctly), which was less
+ than nice. As the underlying commands used inside "git rebase"
+ would fail with a more meaningful error message and advice text
+ when the bogus ident matters, this extra check was removed.
+
+ * "git gc --aggressive" used to limit the delta-chain length to 250,
+ which is way too deep for gaining additional space savings and is
+ detrimental for runtime performance. The limit has been reduced to
+ 50.
+
+ * Documentation for individual configuration variables to control use
+ of color (like `color.grep`) said that their default value is
+ 'false', instead of saying their default is taken from `color.ui`.
+ When we updated the default value for color.ui from 'false' to
+ 'auto' quite a while ago, all of them broke. This has been
+ corrected.
+
+ * The pretty-format specifier "%C(auto)" used by the "log" family of
+ commands to enable coloring of the output is taught to also issue a
+ color-reset sequence to the output.
+
+ * A shell script example in check-ref-format documentation has been
+ fixed.
+
+ * "git checkout <word>" does not follow the usual disambiguation
+ rules when the <word> can be both a rev and a path, to allow
+ checking out a branch 'foo' in a project that happens to have a
+ file 'foo' in the working tree without having to disambiguate.
+ This was poorly documented and the check was incorrect when the
+ command was run from a subdirectory.
+
+ * Some codepaths in "git diff" used regexec(3) on a buffer that was
+ mmap(2)ed, which may not have a terminating NUL, leading to a read
+ beyond the end of the mapped region. This was fixed by introducing
+ a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND
+ extension.
+
+ * The procedure to build Git on Mac OS X for Travis CI hardcoded the
+ internal directory structure we assumed HomeBrew uses, which was a
+ no-no. The procedure has been updated to ask HomeBrew things we
+ need to know to fix this.
+
+ * When "git rebase -i" is given a broken instruction, it told the
+ user to fix it with "--edit-todo", but didn't say what the step
+ after that was (i.e. "--continue").
+
+ * Documentation around tools to import from CVS was fairly outdated.
+
+ * "git clone --recurse-submodules" lost the progress eye-candy in
+ a recent update, which has been corrected.
+
+ * A low-level function verify_packfile() was meant to show errors
+ that were detected without dying itself, but under some conditions
+ it didn't and died instead, which has been fixed.
+
+ * When "git fetch" tries to find where the history of the repository
+ it runs in has diverged from what the other side has, it has a
+ mechanism to avoid digging too deep into irrelevant side branches.
+ This however did not work well over the "smart-http" transport due
+ to a design bug, which has been fixed.
+
+ * In the codepath that comes up with the hostname to be used in an
+ e-mail when the user didn't tell us, we looked at the ai_canonname
+ field in struct addrinfo without making sure it is not NULL first.
+
+ * "git worktree", even though it used the default_abbrev setting that
+ ought to be affected by the core.abbrev configuration variable, ignored
+ the variable setting. The command has been taught to read the
+ default set of configuration variables to correct this.
+
+ * "git init" tried to record core.worktree in the repository's
+ 'config' file when the GIT_WORK_TREE environment variable was set and
+ it was different from where GIT_DIR appears as ".git" at its top,
+ but the logic was faulty when .git is a "gitdir:" file that points
+ at the real place, causing trouble in working trees that are
+ managed by "git worktree". This has been corrected.
+
+ * Codepaths that read from an on-disk loose object were too loose in
+ validating that they are reading a proper object file and
+ sometimes read past the data they read from the disk, which has
+ been corrected. H/t to Gustavo Grieco for reporting.
+
+ * The original command line syntax for "git merge", which was "git
+ merge <msg> HEAD <parent>...", has been deprecated for quite some
+ time, and "git gui" was the last in-tree user of the syntax. This
+ is finally fixed, so that we can move forward with the deprecation.
+
+ * An author name that has a backslash-quoted double quote in the
+ human readable part ("My \"double quoted\" name"), was not unquoted
+ correctly while applying a patch from a piece of e-mail.
+
+ * Doc update to clarify what "log -3 --reverse" does.
+
+ * Almost everybody uses DEFAULT_ABBREV to refer to the default
+ setting for the abbreviation, but "git blame" peeked into
+ underlying variable bypassing the macro for no good reason.
+
+ * The "graph" API used in "git log --graph" miscounted the number of
+ output columns consumed so far when drawing a padding line, which
+ has been fixed; this did not affect any existing code as nobody
+ tried to write anything after the padding on such a line, though.
+
+ * The code that parses the format parameter of the for-each-ref command
+ has seen a micro-optimization.
+
+ * When we started to use cURL to talk to an imap server, we forgot to explicitly add
+ imap(s):// before the destination. To some folks, that didn't work
+ and the library tried to make HTTP(s) requests instead.
+
+ * The ./configure script generated from configure.ac was taught how
+ to detect support of SSL by libcurl better.
+
+ * The command-line completion script (in contrib/) learned to
+ complete "git cmd ^mas<HT>" to complete the negative end of
+ reference to "git cmd ^master".
+ (merge 49416ad22a cp/completion-negative-refs later to maint).
+
+ * The existing "git fetch --depth=<n>" option was hard to use
+ correctly when making the history of an existing shallow clone
+ deeper. A new option, "--deepen=<n>", has been added to make this
+ easier to use. "git clone" also learned "--shallow-since=<date>"
+ and "--shallow-exclude=<tag>" options to make it easier to specify
+ "I am interested only in the recent N months worth of history" and
+ "Give me only the history since that version".
+ (merge cccf74e2da nd/shallow-deepen later to maint).
+
+ * "git blame --reverse OLD path" is now DWIMmed to show how lines
+ in path in an old revision OLD have survived up to the current
+ commit.
+ (merge e1d09701a4 jc/blame-reverse later to maint).
+
+ * The http.emptyauth configuration variable is a way to allow an empty username to
+ pass when attempting to authenticate using mechanisms like
+ Kerberos. We took an unspecified (NULL) username and sent ":"
+ (i.e. no username, no password) to CURLOPT_USERPWD, but did not do
+ the same when the username is explicitly set to an empty string.
+
+ * "git clone" of a local repository can be done at the filesystem
+ level, but the codepath did not check errors while copying and
+ adjusting the file that lists alternate object stores.
+
+ * Documentation for "git commit" was updated to clarify that "commit
+ -p <paths>" adds to the current contents of the index to come up
+ with what to commit.
+
+ * A stray symbolic link in the $GIT_DIR/refs/ directory could make name
+ resolution loop forever, which has been corrected.
+
+ * The "submodule.<name>.path" stored in .gitmodules is never copied
+ to .git/config and such a key in .git/config has no meaning, but
+ the documentation described it next to submodule.<name>.url
+ as if both belong to .git/config. This has been fixed.
+
+ * In a worktree created via "git
+ worktree", "git checkout" attempts to protect users from confusion
+ by refusing to check out a branch that is already checked out in
+ another worktree. However, this also prevented checking out a
+ branch which is designated as the primary branch of a bare
+ repository, in a worktree that is connected to the bare
+ repository. The check has been corrected to allow it.
+
+ * "git rebase" immediately after "git clone" failed to find the fork
+ point from the upstream.
+
+ * When fetching from a remote that has many tags that are irrelevant
+ to branches we are following, we used to waste way too many cycles
+ checking if the object pointed at by a tag (that we are not
+ going to fetch!) exists in our repository too carefully.
+
+ * Protect our code from over-eager compilers.
+
+ * Recent git allows submodule.<name>.branch to use a special token
+ "." instead of the branch name; the documentation has been updated
+ to describe it.
+
+ * "git send-email" attempts to pick up valid e-mails from the
+ trailers, but people in the real world write non-addresses there, like
+ "Cc: Stable <add@re.ss> # 4.8+", which broke the output depending
+ on the availability and vintage of the Mail::Address perl module.
+ (merge dcfafc5214 mm/send-email-cc-cruft-after-address later to maint).
+
+ * The Travis CI configuration we ship ran the tests with the --verbose
+ option but this risks non-TAP output that happens to be "ok" to be
+ misinterpreted as TAP signalling a test that passed. This resulted
+ in unnecessary failures. This has been corrected by introducing a
+ new mode to run our tests in the test harness to send the verbose
+ output separately to the log file.
+
+ * Some AsciiDoc formatters mishandle a displayed illustration with
+ tabs in it. Adjust a few of them in merge-base documentation to
+ work around them.
+
+ * Fixed a minor regression in "git submodule" that was introduced
+ when more helper functions were reimplemented in C.
+ (merge 77b63ac31e sb/submodule-ignore-trailing-slash later to maint).
+
+ * The code that we have used for the past 10+ years to cycle
+ 4-element ring buffers turns out to be not quite portable in
+ theoretical world.
+ (merge bb84735c80 rs/ring-buffer-wraparound later to maint).
+
+ * "git daemon" used fixed-length buffers to turn URLs to the
+ repository the client asked for into the server side directory
+ paths, using snprintf() to avoid overflowing these buffers, but
+ allowed possibly truncated paths to the directory. This has been
+ tightened to reject such a request that causes an overlong path to be
+ served.
+ (merge 6bdb0083be jk/daemon-path-ok-check-truncation later to maint).
+
+ * Recent update to git-sh-setup (a library of shell functions that
+ are used by our in-tree scripted Porcelain commands) included
+ another shell library git-sh-i18n without specifying where it is,
+ relying on the $PATH. This has been fixed to be more explicit by
+ prefixing with $(git --exec-path) output.
+ (merge 1073094f30 ak/sh-setup-dot-source-i18n-fix later to maint).
+
+ * Fix for a racy false-positive test failure.
+ (merge fdf4f6c79b as/merge-attr-sleep later to maint).
+
+ * Portability update and workaround for builds on recent Mac OS X.
+ (merge a296bc0132 ls/macos-update later to maint).
+
+ * Using a %(HEAD) placeholder in "for-each-ref --format=" option
+ caused the command to segfault when on an unborn branch.
+ (merge 84679d470d jc/for-each-ref-head-segfault-fix later to maint).
+
+ * "git rebase -i" did not work well with the core.commentchar
+ configuration variable for two reasons, both of which have been
+ fixed.
+ (merge 882cd23777 js/rebase-i-commentchar-fix later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+ (merge 5c238e29a8 jk/common-main later to maint).
+ (merge 5a5749e45b ak/pre-receive-hook-template-modefix later to maint).
+ (merge 6d834ac8f1 jk/rebase-config-insn-fmt-docfix later to maint).
+ (merge de9f7fa3b0 rs/commit-pptr-simplify later to maint).
+ (merge 4259d693fc sc/fmt-merge-msg-doc-markup-fix later to maint).
+ (merge 28fab7b23d nd/test-helpers later to maint).
+ (merge c2bb0c1d1e rs/cocci later to maint).
+ (merge 3285b7badb ps/common-info-doc later to maint).
+ (merge 2b090822e8 nd/worktree-lock later to maint).
+ (merge 4bd488ea7c jk/create-branch-remove-unused-param later to maint).
+ (merge 974e0044d6 tk/diffcore-delta-remove-unused later to maint).