Git 2.12 Release Notes
======================

Backward compatibility notes.

 * Use of an empty string that is used for 'everything matches' is
   still warned and Git 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.  That
   is not scheduled to happen in the upcoming release (yet).

 * The historical argument order "git merge <msg> HEAD <commit>..."
   has been deprecated for quite some time, and will be removed in a
   future release.


Updates since v2.11
-------------------

UI, Workflows & Features

 * Various updates to "git p4".

 * "git p4" didn't interact with the internal of .git directory
   correctly in the modern "git-worktree"-enabled world.

 * "git branch --list" and friends learned "--ignore-case" option to
   optionally sort branches and tags case insensitively.

 * In addition to %(subject), %(body), "log --pretty=format:..."
   learned a new placeholder %(trailers).

 * "git rebase" learned "--quit" option, which allows a user to
   remove the metadata left by an earlier "git rebase" that was
   manually aborted without using "git rebase --abort".

 * "git clone --reference $there --recurse-submodules $super" has been
   taught to guess repositories usable as references for submodules of
   $super that are embedded in $there while making a clone of the
   superproject borrow objects from $there; extend the mechanism to
   also allow submodules of these submodules to borrow repositories
   embedded in these clones of the submodules embedded in the clone of
   the superproject.

 * Porcelain scripts written in Perl are getting internationalized.

 * "git merge --continue" has been added as a synonym to "git commit"
   to conclude a merge that has stopped due to conflicts.

 * Finer-grained control of what protocols are allowed for transports
   during clone/fetch/push have been enabled via a new configuration
   mechanism.

 * "git shortlog" learned "--committer" option to group commits by
   committer, instead of author.

 * GitLFS integration with "git p4" has been updated.

 * The isatty() emulation for Windows has been updated to eradicate
   the previous hack that depended on internals of (older) MSVC
   runtime.

 * Some platforms no longer understand "latin-1" that is still seen in
   the wild in e-mail headers; replace them with "iso-8859-1" that is
   more widely known when conversion fails from/to it.
   (merge df3755888b jc/latin-1 later to maint).

 * "git grep" has been taught to optionally recurse into submodules.

 * "git rm" used to refuse to remove a submodule when it has its own
   git repository embedded in its working tree.  It learned to move
   the repository away to $GIT_DIR/modules/ of the superproject
   instead, and allow the submodule to be deleted (as long as there
   will be no loss of local modifications, that is).

 * A recent updates to "git p4" was not usable for older p4 but it
   could be made to work with minimum changes.  Do so.

 * "git diff" learned diff.interHunkContext configuration variable
   that gives the default value for its --inter-hunk-context option.

 * The prereleaseSuffix feature of version comparison that is used in
   "git tag -l" did not correctly when two or more prereleases for the
   same release were present (e.g. when 2.0, 2.0-beta1, and 2.0-beta2
   are there and the code needs to compare 2.0-beta1 and 2.0-beta2).

 * "git submodule push" learned "--recurse-submodules=only option to
   push submodules out without pushing the top-level superproject.

 * "git tag" and "git verify-tag" learned to put GPG verification
   status in their "--format=<placeholders>" output format.

 * An ancient repository conversion tool left in contrib/ has been
   removed.

 * "git show-ref HEAD" used with "--verify" because the user is not
   interested in seeing refs/remotes/origin/HEAD, and used with
   "--head" because the user does not want HEAD to be filtered out,
   i.e. "git show-ref --head --verify HEAD", did not work as expected.


Performance, Internal Implementation, Development Support etc.

 * Commands that operate on a log message and add lines to the trailer
   blocks, such as "format-patch -s", "cherry-pick (-x|-s)", and
   "commit -s", have been taught to use the logic of and share the
   code with "git interpret-trailer".

 * The default Travis-CI configuration specifies newer P4 and GitLFS.

 * The "fast hash" that had disastrous performance issues in some
   corner cases has been retired from the internal diff.

 * The character width table has been updated to match Unicode 9.0

 * Update the procedure to generate "tags" for developer support.
   (merge 046e4c1c09 jk/make-tags-find-sources-tweak later to maint).

 * The codeflow of setting NOATIME and CLOEXEC on file descriptors Git
   opens has been simplified.
   (merge b4d065df03 jc/git-open-cloexec later to maint).

 * "git diff" and its family had two experimental heuristics to shift
   the contents of a hunk to make the patch easier to read.  One of
   them turns out to be better than the other, so leave only the
   "--indent-heuristic" option and remove the other one.
   (merge 3cde4e02ee jc/retire-compaction-heuristics later to maint).

 * A new submodule helper "git submodule embedgitdirs" to make it
   easier to move embedded .git/ directory for submodules in a
   superproject to .git/modules/ (and point the latter with the former
   that is turned into a "gitdir:" file) has been added.

 * "git push \\server\share\dir" has recently regressed and then
   fixed.  A test has retroactively been added for this breakage.

 * Build updates for Cygwin.

 * The implementation of "real_path()" was to go there with chdir(2)
   and call getcwd(3), but this obviously wouldn't be usable in a
   threaded environment.  Rewrite it to manually resolve relative
   paths including symbolic links in path components.

 * Adjust documentation to help AsciiDoctor render better while not
   breaking the rendering done by AsciiDoc.

 * The sequencer machinery has been further enhanced so that a later
   set of patches can start using it to reimplement "rebase -i".

 * Update the definition of the MacOSX test environment used by
   TravisCI.
   (merge 672f51cb83 ls/travis-p4-on-macos later to maint).

 * Rewrite a scripted porcelain "git difftool" in C.
   (merge 94d3997ecc js/difftool-builtin later to maint).


Also contains various documentation updates and code clean-ups.

Fixes since v2.10
-----------------

Unless otherwise noted, all the fixes since v2.9 in the maintenance
track are contained in this release (see the maintenance releases'
notes for details).

 * We often decide if a session is interactive by checking if the
   standard I/O streams are connected to a TTY, but isatty() that
   comes with Windows incorrectly returned true if it is used on NUL
   (i.e. an equivalent to /dev/null).  This has been fixed.

 * "git svn" did not work well with path components that are "0", and
   some configuration variable it uses were not documented.
   (merge ea9a93dcc2 ew/svn-fixes later to maint).

 * "git rev-parse --symbolic" failed with a more recent notation like
   "HEAD^-1" and "HEAD^!".

 * An empty directory in a working tree that can simply be nuked used
   to interfere while merging or cherry-picking a change to create a
   submodule directory there, which has been fixed..

 * The code in "git push" to compute if any commit being pushed in the
   superproject binds a commit in a submodule that hasn't been pushed
   out was overly inefficient, making it unusable even for a small
   project that does not have any submodule but have a reasonable
   number of refs.

 * "git push --dry-run --recurse-submodule=on-demand" wasn't
   "--dry-run" in the submodules.

 * The output from "git worktree list" was made in readdir() order,
   and was unstable.

 * mergetool.<tool>.trustExitCode configuration variable did not apply
   to built-in tools, but now it does.

 * "git p4" LFS support was broken when LFS stores an empty blob.

 * A corner case in merge-recursive regression that crept in
   during 2.10 development cycle has been fixed.

 * Transport with dumb http can be fooled into following foreign URLs
   that the end user does not intend to, especially with the server
   side redirects and http-alternates mechanism, which can lead to
   security issues.  Tighten the redirection and make it more obvious
   to the end user when it happens.

 * Update the error messages from the dumb-http client when it fails
   to obtain loose objects; we used to give sensible error message
   only upon 404 but we now forbid unexpected redirects that needs to
   be reported with something sensible.

 * When diff.renames configuration is on (and with Git 2.9 and later,
   it is enabled by default, which made it worse), "git stash"
   misbehaved if a file is removed and another file with a very
   similar content is added.

 * "git diff --no-index" did not take "--no-abbrev" option.

 * "git difftool --dir-diff" had a minor regression when started from
   a subdirectory, which has been fixed.

 * "git commit --allow-empty --only" (no pathspec) with dirty index
   ought to be an acceptable way to create a new commit that does not
   change any paths, but it was forbidden, perhaps because nobody
   needed it so far.

 * Git 2.11 had a minor regression in "merge --ff-only" that competed
   with another process that simultanously attempted to update the
   index. We used to explain what went wrong with an error message,
   but the new code silently failed.  The error message has been
   resurrected.

 * A pathname that begins with "//" or "\\" on Windows is special but
   path normalization logic was unaware of it.

 * "git pull --rebase", when there is no new commits on our side since
   we forked from the upstream, should be able to fast-forward without
   invoking "git rebase", but it didn't.

 * The way to specify hotkeys to "xxdiff" that is used by "git
   mergetool" has been modernized to match recent versions of xxdiff.

 * Unlike "git am --abort", "git cherry-pick --abort" moved HEAD back
   to where cherry-pick started while picking multiple changes, when
   the cherry-pick stopped to ask for help from the user, and the user
   did "git reset --hard" to a different commit in order to re-attempt
   the operation.

 * Code cleanup in shallow boundary computation.

 * A recent update to receive-pack to make it easier to drop garbage
   objects made it clear that GIT_ALTERNATE_OBJECT_DIRECTORIES cannot
   have a pathname with a colon in it (no surprise!), and this in turn
   made it impossible to push into a repository at such a path.  This
   has been fixed by introducing a quoting mechanism used when
   appending such a path to the colon-separated list.

 * The function usage_msg_opt() has been updated to say "fatal:"
   before the custom message programs give, when they want to die
   with a message about wrong command line options followed by the
   standard usage string.

 * "git index-pack --stdin" needs an access to an existing repository,
   but "git index-pack file.pack" to generate an .idx file that
   corresponds to a packfile does not.

 * Fix for NDEBUG builds.

 * A lazy "git push" without refspec did not internally use a fully
   specified refspec to perform 'current', 'simple', or 'upstream'
   push, causing unnecessary "ambiguous ref" errors.

 * "git p4" misbehaved when swapping a directory and a symbolic link.

 * Even though an fix was attempted in Git 2.9.3 days, but running
   "git difftool --dir-diff" from a subdirectory never worked. This
   has been fixed.

 * "git p4" that tracks multile p4 paths imported a single changelist
   that touches files in these multiple paths as one commit, followed
   by many empty commits.  This has been fixed.

 * A potential but unlikely buffer overflow in Windows port has been
   fixed.

 * When the http server gives an incomplete response to a smart-http
   rpc call, it could lead to client waiting for a full response that
   will never come.  Teach the client side to notice this condition
   and abort the transfer.

 * Compression setting for producing packfiles were spread across
   three codepaths, one of which did not honor any configuration.
   Unify these so that all of them honor core.compression and
   pack.compression variables the same way.
   (merge 8de7eeb54b jc/compression-config later to maint).

 * "git fast-import" sometimes mishandled while rebalancing notes
   tree, which has been fixed.
   (merge 405d7f4af6 mh/fast-import-notes-fix-new later to maint).

 * Recent update to the default abbreviation length that auto-scales
   lacked documentation update, which has been corrected.
   (merge 48d5014dd4 jc/abbrev-autoscale-config later to maint).

 * Leakage of lockfiles in the config subsystem has been fixed.
   (merge c06fa62dfc nd/config-misc-fixes later to maint).

 * It is natural that "git gc --auto" may not attempt to pack
   everything into a single pack, and there is no point in warning
   when the user has configured the system to use the pack bitmap,
   leading to disabling further "gc".
   (merge 1c409a705c dt/disable-bitmap-in-auto-gc later to maint).

 * "git archive" did not read the standard configuration files, and
   failed to notice a file that is marked as binary via the userdiff
   driver configuration.
   (merge 965cba2e7e jk/archive-zip-userdiff-config later to maint).

 * "git blame --porcelain" misidentified the "previous" <commit, path>
   pair (aka "source") when contents came from two or more files.
   (merge 4e76832984 jk/blame-fixes later to maint).

 * "git rebase -i" with a recent update started showing an incorrect
   count when squashing more than 10 commits.
   (merge 356b8ecff1 jk/rebase-i-squash-count-fix later to maint).

 * "git <cmd> @{push}" on a detached HEAD used to segfault; it has
   been corrected to error out with a message.
   (merge b10731f43d km/branch-get-push-while-detached later to maint).

 * Running "git add a/b" when "a" is a submodule correctly errored
   out, but without a meaningful error message.
   (merge 2d81c48fa7 sb/pathspec-errors later to maint).

 * Typing ^C to pager, which usually does not kill it, killed Git and
   took the pager down as a collateral damage in certain process-tree
   structure.  This has been fixed.
   (merge 46df6906f3 jk/execv-dashed-external later to maint).

 * "git mergetool" without any pathspec on the command line that is
   run from a subdirectory became no-op in Git v2.11 by mistake, which
   has been fixed.

 * Retire long unused/unmaintained gitview from the contrib/ area.
   (merge 3120925c25 sb/remove-gitview later to maint).

 * Tighten a test to avoid mistaking an extended ERE regexp engine as
   a PRE regexp engine.
   (merge 7675c7bd01 jk/grep-e-could-be-extended-beyond-posix later to maint).

 * An error message with an ASCII control character like '\r' in it
   can alter the message to hide its early part, which is problematic
   when a remote side gives such an error message that the local side
   will relay with a "remote: " prefix.
   (merge f290089879 jk/vreport-sanitize later to maint).

 * "git fsck" inspects loose objects more carefully now.
   (merge cce044df7f jk/loose-object-fsck later to maint).

 * A crashing bug introduced in v2.11 timeframe has been found (it is
   triggerable only in fast-import) and fixed.
   (merge abd5a00268 jk/clear-delta-base-cache-fix later to maint).

 * With an anticipatory tweak for remotes defined in ~/.gitconfig
   (e.g. "remote.origin.prune" set to true, even though there may or
   may not actually be "origin" remote defined in a particular Git
   repository), "git remote rename" and other commands misinterpreted
   and behaved as if such a non-existing remote actually existed.
   (merge e459b073fb js/remote-rename-with-half-configured-remote later to maint).

 * A few codepaths had to rely on a global variable when sorting
   elements of an array because sort(3) API does not allow extra data
   to be passed to the comparison function.  Use qsort_s() when
   natively available, and a fallback implementation of it when not,
   to eliminate the need, which is a prerequisite for making the
   codepath reentrant.
   (merge 83fc4d64fe rs/qsort-s later to maint).

 * "git fsck --connectivity-check" was not working at all.
   (merge a2b22854bd jk/fsck-connectivity-check-fix later to maint).

 * Other minor doc, test and build updates and code cleanups.
   (merge f2627d9b19 sb/submodule-config-cleanup later to maint).
   (merge 384f1a167b sb/unpack-trees-cleanup later to maint).
   (merge 3f05402ac0 ad/bisect-terms later to maint).
   (merge 874444b704 rh/diff-orderfile-doc later to maint).
   (merge c68d2d7c2b ws/request-pull-code-cleanup later to maint).
   (merge 007ac54401 js/exec-path-coverity-workaround later to maint).
   (merge 1797dc5176 jk/coding-guidelines-update later to maint).
   (merge 1d3f065e0e js/mingw-isatty later to maint).
   (merge 830c912a0e sb/in-core-index-doc later to maint).