Git 2.8 Release Notes
=====================
+Backward compatibility note
+---------------------------
+
+The rsync:// transport has been removed.
+
+
Updates since v2.7
------------------
UI, Workflows & Features
- * "branch --delete" has "branch -d" but "push --delete" does not.
- (merge 38a2559 ps/push-delete-option later to maint).
+ * It turns out "git clone" over rsync transport has been broken when
+ the source repository has packed references for a long time, and
+ nobody noticed nor complained about it.
+
+ * "push" learned that its "--delete" option can be shortened to
+ "-d", just like "branch --delete" and "branch -d" are the same
+ thing.
* "git blame" learned to produce the progress eye-candy when it takes
too much time before emitting the first line of the result.
- (merge aba37f4 ea/blame-progress later to maint).
* "git grep" can now be configured (or told from the command line)
how many threads to use when searching in the working tree files.
- (merge 89f09dd vl/grep-configurable-threads later to maint).
+
+ * Some "git notes" operations, e.g. "git log --notes=<note>", should
+ be able to read notes from any tree-ish that is shaped like a notes
+ tree, but the notes infrastructure required that the argument must
+ be a ref under refs/notes/. Loosen it to require a valid ref only
+ when the operation would update the notes (in which case we must
+ have a place to store the updated notes tree, iow, a ref).
+
+ * "git grep" by default does not fall back to its "--no-index"
+ behavior outside a directory under Git's control (otherwise the
+ user may by mistake end up running a huge recursive search); with a
+ new configuration (set in $HOME/.gitconfig--by definition this
+ cannot be set in the config file per project), this safety can be
+ disabled.
+
+ * "git pull --rebase" has been extended to allow invoking
+ "rebase -i".
+
+ * "git p4" learned to cope with the type of a file getting changed.
+
+ * "git format-patch" learned to notice format.outputDirectory
+ configuration variable. This allows "-o <dir>" option to be
+ omitted on the command line if you always use the same directory in
+ your workflow.
+
+ * "interpret-trailers" has been taught to optionally update a file in
+ place, instead of always writing the result to the standard output.
+
+ * Many commands that read files that are expected to contain text
+ that is generated (or can be edited) by the end user to control
+ their behavior (e.g. "git grep -f <filename>") have been updated
+ to be more tolerant to lines that are terminated with CRLF (they
+ used to treat such a line to contain payload that ends with CR,
+ which is usually not what the users expect).
+
+ * "git notes merge" used to limit the source of the merged notes tree
+ to somewhere under refs/notes/ hierarchy, which was too limiting
+ when inventing a workflow to exchange notes with remote
+ repositories using remote-tracking notes trees (located in e.g.
+ refs/remote-notes/ or somesuch).
+
+ * "git ls-files" learned a new "--eol" option to help diagnose
+ end-of-line problems.
+
+ * "ls-remote" learned an option to show which branch the remote
+ repository advertises as its primary by pointing its HEAD at.
+
+ * New http.proxyAuthMethod configuration variable can be used to
+ specify what authentication method to use, as a way to work around
+ proxies that do not give error response expected by libcurl when
+ CURLAUTH_ANY is used. Also, the codepath for proxy authentication
+ has been taught to use credential API to store the authentication
+ material in user's keyrings.
+
+ * Update the untracked cache subsystem and change its primary UI from
+ "git update-index" to "git config".
+
+ * There were a few "now I am doing this thing" progress messages in
+ the TCP connection code that can be triggered by setting a verbose
+ option internally in the code, but "git fetch -v" and friends never
+ passed the verbose option down to that codepath.
+
+ * Clean/smudge filters defined in a configuration file of lower
+ precedence can now be overridden to be a pass-through no-op by
+ setting the variable to an empty string.
+
+ * A new "<branch>^{/!-<pattern>}" notation can be used to name a
+ commit that is reachable from <branch> that does not match the
+ given <pattern>.
+
+ * The "user.useConfigOnly" configuration variable can be used to
+ force the user to always set user.email & user.name configuration
+ variables, serving as a reminder for those who work on multiple
+ projects and do not want to put these in their $HOME/.gitconfig.
+
+ * "git fetch" and friends that make network connections can now be
+ told to only use ipv4 (or ipv6).
+
+ * Some authentication methods do not need username or password, but
+ libcurl needs some hint that it needs to perform authentication.
+ Supplying an empty username and password string is a valid way to
+ do so, but you can set the http.[<url>.]emptyAuth configuration
+ variable to achieve the same, if you find it cleaner.
+
+ * You can now set http.[<url>.]pinnedpubkey to specify the pinned
+ public key when building with recent enough versions of libcURL.
+
+ * The configuration system has been taught to phrase where it found a
+ bad configuration variable in a better way in its error messages.
+ "git config" learnt a new "--show-origin" option to indicate where
+ the values come from.
+
+ * The "credential-cache" daemon process used to run in whatever
+ directory it happened to start in, but this made umount(2)ing the
+ filesystem that houses the repository harder; now the process
+ chdir()s to the directory that house its own socket on startup.
+
+ * When "git submodule update" did not result in fetching the commit
+ object in the submodule that is referenced by the superproject, the
+ command learned to retry another fetch, specifically asking for
+ that commit that may not be connected to the refs it usually
+ fetches.
+
+ * "git merge-recursive" learned "--no-renames" option to disable its
+ rename detection logic.
+
+ * Across the transition at around Git version 2.0, the user used to
+ get a pretty loud warning when running "git push" without setting
+ push.default configuration variable. We no longer warn because the
+ transition was completed a long time ago.
+
+ * README has been renamed to README.md and its contents got tweaked
+ slightly to make it easier on the eyes.
Performance, Internal Implementation, Development Support etc.
* Add a framework to spawn a group of processes in parallel, and use
it to run "git fetch --recurse-submodules" in parallel.
- * A slight update to the Makefile to mark "phoney" targets
- as such correctly.
+ * A slight update to the Makefile to mark ".PHONY" targets as such
+ correctly.
+
+ * In-core storage of the reverse index for .pack files (which lets
+ you go from a pack offset to an object name) has been streamlined.
+
+ * d95138e6 (setup: set env $GIT_WORK_TREE when work tree is set, like
+ $GIT_DIR, 2015-06-26) attempted to work around a glitch in alias
+ handling by overwriting GIT_WORK_TREE environment variable to
+ affect subprocesses when set_git_work_tree() gets called, which
+ resulted in a rather unpleasant regression to "clone" and "init".
+ Try to address the same issue by always restoring the environment
+ and respawning the real underlying command when handling alias.
+
+ * The low-level code that is used to create symbolic references has
+ been updated to share more code with the code that deals with
+ normal references.
+
+ * strbuf_getline() and friends have been redefined to make it easier
+ to identify which callsite of (new) strbuf_getline_lf() should
+ allow and silently ignore carriage-return at the end of the line to
+ help users on DOSsy systems.
+
+ * "git shortlog" used to accumulate various pieces of information
+ regardless of what was asked to be shown in the final output. It
+ has been optimized by noticing what need not to be collected
+ (e.g. there is no need to collect the log messages when showing
+ only the number of changes).
+
+ * "git checkout $branch" (and other operations that share the same
+ underlying machinery) has been optimized.
+
+ * Automated tests in Travis CI environment has been optimized by
+ persisting runtime statistics of previous "prove" run, executing
+ tests that take longer before other ones; this reduces the total
+ wallclock time.
+
+ * Test scripts have been updated to remove assumptions that are not
+ portable between Git for POSIX and Git for Windows, or to skip ones
+ with expectations that are not satisfiable on Git for Windows.
+
+ * Some calls to strcpy(3) triggers a false warning from static
+ analyzers that are less intelligent than humans, and reducing the
+ number of these false hits helps us notice real issues. A few
+ calls to strcpy(3) in a couple of protrams that are already safe
+ has been rewritten to avoid false warnings.
+
+ * The "name_path" API was an attempt to reduce the need to construct
+ the full path out of a series of path components while walking a
+ tree hierarchy, but over time made less efficient because the path
+ needs to be flattened, e.g. to be compared with another path that
+ is already flat. The API has been removed and its users have been
+ rewritten to simplify the overall code complexity.
+
+ * Help those who debug http(s) part of the system.
+ (merge 0054045 sp/remote-curl-ssl-strerror later to maint).
+
+ * The internal API to interact with "remote.*" configuration
+ variables has been streamlined.
+
+ * The ref-filter's format-parsing code has been refactored, in
+ preparation for "branch --format" and friends.
+
+ * Traditionally, the tests that try commands that work on the
+ contents in the working tree were named with "worktree" in their
+ filenames, but with the recent addition of "git worktree"
+ subcommand, whose tests are also named similarly, it has become
+ harder to tell them apart. The traditional tests have been renamed
+ to use "work-tree" instead in an attempt to differentiate them.
+ (merge 5549029 mg/work-tree-tests later to maint).
+
+ * Many codepaths forget to check return value from git_config_set();
+ the function is made to die() to make sure we do not proceed when
+ setting a configuration variable failed.
+ (merge 3d18064 ps/config-error later to maint).
+
+ * Handling of errors while writing into our internal asynchronous
+ process has been made more robust, which reduces flakiness in our
+ tests.
+ (merge 43f3afc jk/epipe-in-async later to maint).
+
+ * There is a new DEVELOPER knob that enables many compiler warning
+ options in the Makefile.
+
+ * The way the test scripts configure the Apache web server has been
+ updated to work also for Apache 2.4 running on RedHat derived
+ distros.
+
+ * Out of maintenance gcc on OSX 10.6 fails to compile the code in
+ 'master'; work it around by using clang by default on the platform.
+
+ * The "name_path" API was an attempt to reduce the need to construct
+ the full path out of a series of path components while walking a
+ tree hierarchy, but over time made less efficient because the path
+ needs to be flattened, e.g. to be compared with another path that
+ is already flat, in many cases. The API has been removed and its
+ users have been rewritten to simplify the overall code complexity.
+ This incidentally also closes some heap-corruption holes.
+
+ * Recent versions of GNU grep is pickier than before to decide if a
+ file is "binary" and refuse to give line-oriented hits when we
+ expect it to, unless explicitly told with "-a" option. As our
+ scripted Porcelains use sane_grep wrapper for line-oriented data,
+ even when the line may contain non-ASCII payload we took from
+ end-user data, use "grep -a" to implement sane_grep wrapper when
+ using an implementation of "grep" that takes the "-a" option.
+
Also contains various documentation updates and code clean-ups.
exporting GIT_WORK_TREE to point at the root of the working tree,
interfering when they tried to use a different working tree without
setting GIT_WORK_TREE environment themselves.
- (merge df1e6ea nd/stop-setenv-work-tree later to maint).
+
+ * The "exclude_list" structure has the usual "alloc, nr" pair of
+ fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot
+ to reset 'alloc' to 0 when it cleared 'nr' to discard the managed
+ array.
+
+ * Paths that have been told the index about with "add -N" are not
+ quite yet in the index, but a few commands behaved as if they
+ already are in a harmful way.
+
+ * "git send-email" was confused by escaped quotes stored in the alias
+ files saved by "mutt", which has been corrected.
+
+ * A few non-portable C construct have been spotted by clang compiler
+ and have been fixed.
+
+ * The documentation has been updated to hint the connection between
+ the '--signoff' option and DCO.
+
+ * "git reflog" incorrectly assumed that all objects that used to be
+ at the tip of a ref must be commits, which caused it to segfault.
+
+ * The ignore mechanism saw a few regressions around untracked file
+ listing and sparse checkout selection areas in 2.7.0; the change
+ that is responsible for the regression has been reverted.
+
+ * Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR
+ (e.g. COMMIT_EDITMSG) that is meant to be left after the command is
+ done. This however did not work well if the repository is set to
+ be shared with core.sharedRepository and the umask of the previous
+ user is tighter. They have been made to work better by calling
+ unlink(2) and retrying after fopen(3) fails with EPERM.
+
+ * Asking gitweb for a nonexistent commit left a warning in the server
+ log.
+
+ Somebody may want to follow this up with an additional test, perhaps?
+ IIRC, we do test that no Perl warnings are given to the server log,
+ so this should have been caught if our test coverage were good.
+
+ * "git rebase", unlike all other callers of "gc --auto", did not
+ ignore the exit code from "gc --auto".
+
+ * Many codepaths that run "gc --auto" before exiting kept packfiles
+ mapped and left the file descriptors to them open, which was not
+ friendly to systems that cannot remove files that are open. They
+ now close the packs before doing so.
+
+ * A recent optimization to filter-branch in v2.7.0 introduced a
+ regression when --prune-empty filter is used, which has been
+ corrected.
+
+ * The description for SANITY prerequisite the test suite uses has
+ been clarified both in the comment and in the implementation.
+
+ * "git tag" started listing a tag "foo" as "tags/foo" when a branch
+ named "foo" exists in the same repository; remove this unnecessary
+ disambiguation, which is a regression introduced in v2.7.0.
+
+ * The way "git svn" uses auth parameter was broken by Subversion
+ 1.9.0 and later.
+
+ * The "split" subcommand of "git subtree" (in contrib/) incorrectly
+ skipped merges when it shouldn't, which was corrected.
+
+ * A few options of "git diff" did not work well when the command was
+ run from a subdirectory.
+
+ * The command line completion learned a handful of additional options
+ and command specific syntax.
+
+ * dirname() emulation has been added, as Msys2 lacks it.
+
+ * The underlying machinery used by "ls-files -o" and other commands
+ has been taught not to create empty submodule ref cache for a
+ directory that is not a submodule. This removes a ton of wasted
+ CPU cycles.
+
+ * "git worktree" had a broken code that attempted to auto-fix
+ possible inconsistency that results from end-users moving a
+ worktree to different places without telling Git (the original
+ repository needs to maintain back-pointers to its worktrees,
+ but "mv" run by end-users who are not familiar with that fact
+ will obviously not adjust them), which actually made things
+ worse when triggered.
+
+ * The low-level merge machinery has been taught to use CRLF line
+ termination when inserting conflict markers to merged contents that
+ are themselves CRLF line-terminated.
+
+ * "git push --force-with-lease" has been taught to report if the push
+ needed to force (or fast-forwarded).
+
+ * The emulated "yes" command used in our test scripts has been
+ tweaked not to spend too much time generating unnecessary output
+ that is not used, to help those who test on Windows where it would
+ not stop until it fills the pipe buffer due to lack of SIGPIPE.
+
+ * The documentation for "git clean" has been corrected; it mentioned
+ that .git/modules/* are removed by giving two "-f", which has never
+ been the case.
+
+ * The vimdiff backend for "git mergetool" has been tweaked to arrange
+ and number buffers in the order that would match the expectation of
+ majority of people who read left to right, then top down and assign
+ buffers 1 2 3 4 "mentally" to local base remote merge windows based
+ on that order.
+
+ * "git show 'HEAD:Foo[BAR]Baz'" did not interpret the argument as a
+ rev, i.e. the object named by the the pathname with wildcard
+ characters in a tree object.
+ (merge aac4fac nd/dwim-wildcards-as-pathspecs later to maint).
+
+ * "git rev-parse --git-common-dir" used in the worktree feature
+ misbehaved when run from a subdirectory.
+ (merge 17f1365 nd/git-common-dir-fix later to maint).
+
+ * "git worktree add -B <branchname>" did not work.
+
+ * The "v(iew)" subcommand of the interactive "git am -i" command was
+ broken in 2.6.0 timeframe when the command was rewritten in C.
+ (merge 708b8cc jc/am-i-v-fix later to maint).
+
+ * "git merge-tree" used to mishandle "both sides added" conflict with
+ its own "create a fake ancestor file that has the common parts of
+ what both sides have added and do a 3-way merge" logic; this has
+ been updated to use the usual "3-way merge with an empty blob as
+ the fake common ancestor file" approach used in the rest of the
+ system.
+ (merge 907681e jk/no-diff-emit-common later to maint).
+
+ * The memory ownership rule of fill_textconv() API, which was a bit
+ tricky, has been documented a bit better.
+ (merge a64e6a4 jk/more-comments-on-textconv later to maint).
+
+ * Update various codepaths to avoid manually-counted malloc().
+ (merge 08c95df jk/tighten-alloc later to maint).
+
+ * The documentation did not clearly state that the 'simple' mode is
+ now the default for "git push" when push.default configuration is
+ not set.
+ (merge f6b1fb3 mm/push-simple-doc later to maint).
+
+ * Recent versions of GNU grep are pickier when their input contains
+ arbitrary binary data, which some of our tests uses. Rewrite the
+ tests to sidestep the problem.
+ (merge 3b1442d jk/grep-binary-workaround-in-test later to maint).
+
+ * A helper function "git submodule" uses since v2.7.0 to list the
+ modules that match the pathspec argument given to its subcommands
+ (e.g. "submodule add <repo> <path>") has been fixed.
+ (merge 2b56bb7 sb/submodule-module-list-fix later to maint).
+
+ * "git config section.var value" to set a value in per-repository
+ configuration file failed when it was run outside any repository,
+ but didn't say the reason correctly.
+ (merge 638fa62 js/config-set-in-non-repository later to maint).
+
+ * The code to read the pack data using the offsets stored in the pack
+ idx file has been made more carefully check the validity of the
+ data in the idx.
+ (merge 7465feb jk/pack-idx-corruption-safety later to maint).
+
+ * Other minor clean-ups and documentation updates
+ (merge f459823 ak/extract-argv0-last-dir-sep later to maint).
+ (merge 63ca1c0 ak/git-strip-extension-from-dashed-command later to maint).
+ (merge 4867f11 ps/plug-xdl-merge-leak later to maint).
+ (merge 4938686 dt/initial-ref-xn-commit-doc later to maint).
+ (merge 9537f21 ma/update-hooks-sample-typofix later to maint).