"git log" by default enables the rename detection; you can still use
"diff.renames" configuration variable to disable this.
+Merging two branches that have no common ancestor with "git merge" is
+by default forbidden now to prevent creating such an unusual merge by
+mistake.
+
+The output formats of "git log" that indents the commit log message by
+4 spaces now expands HT in the log message by default. You can use
+the "--no-expand-tabs" option to disable this.
+
+"git commit-tree" plumbing command required the user to always sign
+its result when the user sets the commit.gpgsign configuration
+variable, which was an ancient mistake, which this release corrects.
+A script that drives commit-tree, if it relies on this mistake, now
+needs to read commit.gpgsign and pass the -S option as necessary.
+
Updates since v2.8
------------------
UI, Workflows & Features
+ * Comes with git-multimail 1.3.1 (in contrib/).
+
* The end-user facing Porcelain level commands like "diff" and "log"
now enables the rename detection by default.
* A new "interactive.diffFilter" configuration can be used to
customize the diff shown in "git add -i" session.
+ * "git p4" now allows P4 author names to be mapped to Git author
+ names.
+
+ * "git rebase -x" can be used without passing "-i" option.
+
+ * "git -c credential.<var>=<value> submodule" can now be used to
+ propagate configuration variables related to credential helper
+ down to the submodules.
+
+ * "git tag" can create an annotated tag without explicitly given an
+ "-a" (or "-s") option (i.e. when a tag message is given). A new
+ configuration variable, tag.forceSignAnnotated, can be used to tell
+ the command to create signed tag in such a situation.
+
+ * "git merge" used to allow merging two branches that have no common
+ base by default, which led to a brand new history of an existing
+ project created and then get pulled by an unsuspecting maintainer,
+ which allowed an unnecessary parallel history merged into the
+ existing project. The command has been taught not to allow this by
+ default, with an escape hatch "--allow-unrelated-histories" option
+ to be used in a rare event that merges histories of two projects
+ that started their lives independently.
+
+ * "git pull" has been taught to pass --allow-unrelated-histories
+ option to underlying "git merge".
+
+ * "git apply -v" learned to report paths in the patch that were
+ skipped via --include/--exclude mechanism or being outside the
+ current working directory.
+
+ * Shell completion (in contrib/) updates.
+
+ * The commit object name reported when "rebase -i" stops has been
+ shortened.
+
+ * "git worktree add" can be given "--no-checkout" option to only
+ create an empty worktree without checking out the files.
+
+ * "git mergetools" learned to drive ExamDiff.
+
+ * "git pull --rebase" learned "--[no-]autostash" option, so that
+ the rebase.autostash configuration variable set to true can be
+ overridden from the command line.
+
+ * When "git log" shows the log message indented by 4-spaces, the
+ remainder of a line after a HT does not align in the way the author
+ originally intended. The command now expands tabs by default in
+ such a case, and allows the users to override it with a new option,
+ "--no-expand-tabs".
+
+ * "git send-email" now uses a more readable timestamps when
+ formulating a message ID.
+
+ * "git rerere" can encounter two or more files with the same conflict
+ signature that have to be resolved in different ways, but there was
+ no way to record these separate resolutions.
+ (merge d9d501b068 jc/rerere-multi later to maint).
+
+ * "git p4" learned to record P4 jobs in Git commit that imports from
+ the history in Perforce.
+
+ * "git describe --contains" often made a hard-to-justify choice of
+ tag to give name to a given commit, because it tried to come up
+ with a name with smallest number of hops from a tag, causing an old
+ commit whose close descendant that is recently tagged were not
+ described with respect to an old tag but with a newer tag. It did
+ not help that its computation of "hop" count was further tweaked to
+ penalize being on a side branch of a merge. The logic has been
+ updated to favor using the tag with the oldest tagger date, which
+ is a lot easier to explain to the end users: "We describe a commit
+ in terms of the (chronologically) oldest tag that contains the
+ commit."
+ (merge 7550424 js/name-rev-use-oldest-ref later to maint).
+
+ * "git clone" learned "--shallow-submodules" option.
+
+ * HTTP transport clients learned to throw extra HTTP headers at the
+ server, specified via http.extraHeader configuration variable.
+
+ * Patch output from "git diff" and friends has been tweaked to be
+ more readable by using a blank line as a strong hint that the
+ contents before and after it belong to a logically separate unit.
+
+ * A new configuration variable core.hooksPath allows customizing
+ where the hook directory is.
+
+ * An earlier addition of "sanitize_submodule_env" with 14111fc4 (git:
+ submodule honor -c credential.* from command line, 2016-02-29)
+ turned out to be a convoluted no-op; implement what it wanted to do
+ correctly, and stop filtering settings given via "git -c var=val".
+
+ * "git commit --dry-run" reported "No, no, you cannot commit." in one
+ case where "git commit" would have allowed you to commit, and this
+ improves it a little bit ("git commit --dry-run --short" still does
+ not give you the correct answer, for example). This is a stop-gap
+ measure in that "commit --short --dry-run" still gives an incorrect
+ result.
+
+ * The experimental "multiple worktree" feature gains more safety to
+ forbid operations on a branch that is checked out or being actively
+ worked on elsewhere, by noticing that e.g. it is being rebased.
+
+ * "git format-patch" learned a new "--base" option to record what
+ (public, well-known) commit the original series was built on in
+ its output.
+
+ * "git commit" learned to pay attention to "commit.verbose"
+ configuration variable and act as if "--verbose" option was
+ given from the command line.
+
+ * Give hints to GMail users with two-factor auth enabled that
+ they need app-specific-password when using send-email.
+
Performance, Internal Implementation, Development Support etc.
* The embedded args argv-array in the child process is used to build
the command line to run pack-objects instead of using a separate
array of strings.
- (merge 65a3629 mp/upload-pack-use-embedded-args later to maint).
* A test for tags has been restructured so that more parts of it can
easily be run on a platform without a working GnuPG.
- (merge 618310a es/test-gpg-tags later to maint).
* The startup_info data, which records if we are working inside a
repository (among other things), are now uniformly available to Git
subcommand implementations, and Git avoids attempting to touch
references when we are not in a repository.
- (merge 11e6b3f jk/startup-info later to maint).
+
+ * The command line argument parser for "receive-pack" has been
+ rewritten to use parse-options.
+
+ * A major part of "git submodule update" has been ported to C to take
+ advantage of the recently added framework to run download tasks in
+ parallel.
+
+ * Rename bunch of tests on "git clone" for better organization.
+
+ * The tests that involve running httpd leaked the system-wide
+ configuration in /etc/gitconfig to the tested environment.
+
+ * Build updates for MSVC.
+
+ * The repository set-up sequence has been streamlined (the biggest
+ change is that there is no longer git_config_early()), so that we
+ do not attempt to look into refs/* when we know we do not have a
+ Git repository.
+
+ * Code restructuring around the "refs" area to prepare for pluggable
+ refs backends.
+
+ * Sources to many test helper binaries (and the generated helpers)
+ have been moved to t/helper/ subdirectory to reduce clutter at the
+ top level of the tree.
+
+ * Unify internal logic between "git tag -v" and "git verify-tag"
+ commands by making one directly call into the other.
+ (merge bef234b st/verify-tag later to maint).
+
+ * "merge-recursive" strategy incorrectly checked if a path that is
+ involved in its internal merge exists in the working tree.
+
+ * The test scripts for "git p4" (but not "git p4" implementation
+ itself) has been updated so that they would work even on a system
+ where the installed version of Python is python 3.
+
+ * As nobody maintains our in-tree git.spec.in and distros use their
+ own spec file, we stopped pretending that we support "make rpm".
+
+ * Move from unsigned char[20] to struct object_id continues.
+
+ * Update of "git submodule" to move pieces of logic to C continues.
+
+ * The code for warning_errno/die_errno has been refactored and a new
+ error_errno() reporting helper is introduced.
+ (merge 1da045f nd/error-errno later to maint).
+
+ * Running tests with '-x' option to trace the individual command
+ executions is a useful way to debug test scripts, but some tests
+ that capture the standard error stream and check what the command
+ said can be broken with the trace output mixed in. When running
+ our tests under "bash", however, we can redirect the trace output
+ to another file descriptor to keep the standard error of programs
+ being tested intact.
+ (merge d88785e jk/test-send-sh-x-trace-elsewhere later to maint).
+
+ * t0040 had too many unnecessary repetitions in its test data. Teach
+ test-parse-options program so that a caller can tell what it
+ expects in its output, so that these repetitions can be cleaned up.
+
+ * Add perf test for "rebase -i"
+
+ * Common mistakes when writing gitlink: in our documentation are
+ found by "make check-docs".
+
+ * t9xxx series has been updated primarily for readability, while
+ fixing small bugs in it. A few scripted Porcelains have also been
+ updated to fix possible bugs around their use of "test -z" and
+ "test -n".
+
+ * CI test was taught to run git-svn tests.
Also contains various documentation updates and code clean-ups.
* "git config --get-urlmatch", unlike other variants of the "git
config --get" family, did not signal error with its exit status
when there was no matching configuration.
- (merge 24990b2 jk/config-get-urlmatch later to maint).
* The "--local-env-vars" and "--resolve-git-dir" options of "git
rev-parse" failed to work outside a repository when the command's
option parsing was rewritten in 1.8.5 era.
- (merge fc7d47f jk/rev-parse-local-env-vars later to maint).
* "git index-pack --keep[=<msg>] pack-$name.pack" simply did not work.
- (merge 0e94242 jc/maint-index-pack-keep later to maint).
* Fetching of history by naming a commit object name directly didn't
work across remote-curl transport.
- (merge 754ecb1 gf/fetch-pack-direct-object-fetch later to maint).
* A small memory leak in an error codepath has been plugged in xdiff
code.
- (merge 87f1625 rj/xdiff-prepare-plug-leak-on-error-codepath later to maint).
* strbuf_getwholeline() did not NUL-terminate the buffer on certain
corner cases in its error codepath.
- (merge b709043 jk/getwholeline-getdelim-empty later to maint).
+
+ * "git mergetool" did not work well with conflicts that both sides
+ deleted.
+
+ * "git send-email" had trouble parsing alias file in mailrc format
+ when lines in it had trailing whitespaces on them.
+
+ * When "git merge --squash" stopped due to conflict, the concluding
+ "git commit" failed to read in the SQUASH_MSG that shows the log
+ messages from all the squashed commits.
+
+ * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
+ nothing into an unborn history (which is arguably unusual usage,
+ which perhaps was the reason why nobody noticed it).
+
+ * When "git worktree" feature is in use, "git branch -d" allowed
+ deletion of a branch that is checked out in another worktree,
+ which was wrong.
+
+ * When "git worktree" feature is in use, "git branch -m" renamed a
+ branch that is checked out in another worktree without adjusting
+ the HEAD symbolic ref for the worktree.
+
+ * "git diff -M" used to work better when two originally identical
+ files A and B got renamed to X/A and X/B by pairing A to X/A and B
+ to X/B, but this was broken in the 2.0 timeframe.
+
+ * "git send-pack --all <there>" was broken when its command line
+ option parsing was written in the 2.6 timeframe.
+
+ * "git format-patch --help" showed `-s` and `--no-patch` as if these
+ are valid options to the command. We already hide `--patch` option
+ from the documentation, because format-patch is about showing the
+ diff, and the documentation now hides these options as well.
+
+ * When running "git blame $path" with unnormalized data in the index
+ for the path, the data in the working tree was blamed, even though
+ "git add" would not have changed what is already in the index, due
+ to "safe crlf" that disables the line-end conversion. It has been
+ corrected.
+
+ * A change back in version 2.7 to "git branch" broke display of a
+ symbolic ref in a non-standard place in the refs/ hierarchy (we
+ expect symbolic refs to appear in refs/remotes/*/HEAD to point at
+ the primary branch the remote has, and as .git/HEAD to point at the
+ branch we locally checked out).
+
+ * A partial rewrite of "git submodule" in the 2.7 timeframe changed
+ the way the gitdir: pointer in the submodules point at the real
+ repository location to use absolute paths by accident. This has
+ been corrected.
+
+ * "git commit" misbehaved in a few minor ways when an empty message
+ is given via -m '', all of which has been corrected.
+
+ * Support for CRAM-MD5 authentication method in "git imap-send" did
+ not work well.
+
+ * Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
+ we use in imap-send, which has been adjusted for the change.
+
+ * The socks5:// proxy support added back in 2.6.4 days was not aware
+ that socks5h:// proxies behave differently.
+
+ * "git config" had a codepath that tried to pass a NULL to
+ printf("%s"), which nobody seems to have noticed.
+
+ * On Cygwin, object creation uses the "create a temporary and then
+ rename it to the final name" pattern, not "create a temporary,
+ hardlink it to the final name and then unlink the temporary"
+ pattern.
+
+ This is necessary to use Git on Windows shared directories, and is
+ already enabled for the MinGW and plain Windows builds. It also
+ has been used in Cygwin packaged versions of Git for quite a while.
+ See http://thread.gmane.org/gmane.comp.version-control.git/291853
+
+ * "merge-octopus" strategy did not ensure that the index is clean
+ when merge begins.
+
+ * When "git merge" notices that the merge can be resolved purely at
+ the tree level (without having to merge blobs) and the resulting
+ tree happens to already exist in the object store, it forgot to
+ update the index, which lead to an inconsistent state for later
+ operations.
+
+ * "git submodule" reports the paths of submodules the command
+ recurses into, but this was incorrect when the command was not run
+ from the root level of the superproject.
+
+ * The "user.useConfigOnly" configuration variable makes it an error
+ if users do not explicitly set user.name and user.email. However,
+ its check was not done early enough and allowed another error to
+ trigger, reporting that the default value we guessed from the
+ system setting was unusable. This was a suboptimal end-user
+ experience as we want the users to set user.name/user.email without
+ relying on the auto-detection at all.
+
+ * "git mv old new" did not adjust the path for a submodule that lives
+ as a subdirectory inside old/ directory correctly.
+
+ * "git replace -e" did not honour "core.editor" configuration.
+
+ * "git push" from a corrupt repository that attempts to push a large
+ number of refs deadlocked; the thread to relay rejection notices
+ for these ref updates blocked on writing them to the main thread,
+ after the main thread at the receiving end notices that the push
+ failed and decides not to read these notices and return a failure.
+
+ * mmap emulation on Windows has been optimized and work better without
+ consuming paging store when not needed.
+
+ * A question by "git send-email" to ask the identity of the sender
+ has been updated.
+
+ * UI consistency improvements for "git mergetool".
+
+ * "git rebase -m" could be asked to rebase an entire branch starting
+ from the root, but failed by assuming that there always is a parent
+ commit to the first commit on the branch.
+ (merge 79f4344 bw/rebase-merge-entire-branch later to maint).
+
+ * Fix a broken "p4 lfs" test.
+
+ * Recent update to Git LFS broke "git p4" by changing the output from
+ its "lfs pointer" subcommand.
+
+ * "git fetch" test t5510 was flaky while running a (forced) automagic
+ garbage collection.
+
+ * Documentation updates to help contributors setting up Travis CI
+ test for their patches.
+
+ * Some multi-byte encoding can have a backslash byte as a later part
+ of one letter, which would confuse "highlight" filter used in
+ gitweb.
+
+ * "git commit-tree" plumbing command required the user to always sign
+ its result when the user sets the commit.gpgsign configuration
+ variable, which was an ancient mistake. Rework "git rebase" that
+ relied on this mistake so that it reads commit.gpgsign and pass (or
+ not pass) the -S option to "git commit-tree" to keep the end-user
+ expectation the same, while teaching "git commit-tree" to ignore
+ the configuration variable. This will stop requiring the users to
+ sign commit objects used internally as an implementation detail of
+ "git stash".
+ (merge 6694856 jc/commit-tree-ignore-commit-gpgsign later to maint).
+
+ * "http.cookieFile" configuration variable clearly wants a pathname,
+ but we forgot to treat it as such by e.g. applying tilde expansion.
+ (merge e5a39ad bn/http-cookiefile-config later to maint).
+
+ * Consolidate description of tilde-expansion that is done to
+ configuration variables that take pathname to a single place.
+ (merge dca83ab jc/config-pathname-type later to maint).
+
+ * Correct faulty recommendation to use "git submodule deinit ." when
+ de-initialising all submodules, which would result in a strange
+ error message in a pathological corner case.
+ (merge f6a5279 sb/submodule-deinit-all later to maint).
+
+ * Many 'linkgit:<git documentation page>' references were broken,
+ which are all fixed with this.
+ (merge 1cca17d jc/linkgit-fix later to maint).
+
+ * "git rerere" can get confused by conflict markers deliberately left
+ by the inner merge step, because they are indistinguishable from
+ the real conflict markers left by the outermost merge which are
+ what the end user and "rerere" need to look at. This was fixed by
+ making the conflict markers left by the inner merges a bit longer.
+ (merge 0f9fd5c jc/ll-merge-internal later to maint).
+
+ * CI test was taught to build documentation pages.
+ (merge b98712b ls/travis-build-doc later to maint).
+
+ * "git fsck" learned to catch NUL byte in a commit object as
+ potential error and warn.
+ (merge 6d2d780 jc/fsck-nul-in-commit later to maint).
+
+ * Portability enhancement for "rebase -i" to help platforms whose
+ shell does not like "for i in <empty>" (which is not POSIX-kosher).
+ (merge 8e98b35 jk/rebase-interative-eval-fix later to maint).
+
+ * On Windows, .git and optionally any files whose name starts with a
+ dot are now marked as hidden, with a core.hideDotFiles knob to
+ customize this behaviour.
+ (merge ebf31e7 js/windows-dotgit later to maint).
+
+ * Documentation for "git merge --verify-signatures" has been updated
+ to clarify that the signature of only the commit at the tip is
+ verified. Also the phrasing used for signature and key validity is
+ adjusted to align with that used by OpenPGP.
+ (merge 05a5869 kf/gpg-sig-verification-doc later to maint).
+
+ * A couple of bugs around core.autocrlf have been fixed.
+ (merge caa47ad tb/core-eol-fix later to maint).
+
+ * Many commands normalize command line arguments from NFD to NFC
+ variant of UTF-8 on OSX, but commands in the "diff" family did
+ not, causing "git diff $path" to complain that no such path is
+ known to Git. They have been taught to do the normalization.
+ (merge 90a78b8 ar/diff-args-osx-precompose later to maint).
+
+ * "git difftool" learned to handle unmerged paths correctly in
+ dir-diff mode.
+ (merge 366f9ce da/difftool later to maint).
+
+ * The "are we talking with TTY, doing an interactive session?"
+ detection has been updated to work better for "Git for Windows".
+ (merge f7f90e0 kb/msys2-tty later to maint).
+
+ * We forgot to add "git log --decorate=auto" to documentation when we
+ added the feature back in v2.1.0 timeframe.
+ (merge 462cbb4 rj/log-decorate-auto later to maint).
* Other minor clean-ups and documentation updates
- (merge aed7480 mm/lockfile-error-message later to maint).
- (merge bfee614 jc/index-pack later to maint).
+ (merge 832c0e5 lp/typofixes later to maint).
+ (merge f5ee54a sb/z-is-gnutar-ism later to maint).
+ (merge 2e3926b va/i18n-misc-updates later to maint).
+ (merge f212dcc bn/config-doc-tt-varnames later to maint).
+ (merge f54bea4 nd/remote-plural-ours-plus-theirs later to maint).
+ (merge 2bb0518 ak/t4151-ls-files-could-be-empty later to maint).
+ (merge 4df4313 jc/test-seq later to maint).
+ (merge a75a308 tb/t5601-sed-fix later to maint).
+ (merge 6c1fbe1 va/i18n-remote-comment-to-align later to maint).
+ (merge dee2303 va/mailinfo-doc-typofix later to maint).