Updates since v2.21
-------------------
+Backward compatibility note
+
+ * The filter specification "--filter=sparse:path=<path>" used to
+ create a lazy/partial clone has been removed. Using a blob that is
+ part of the project as sparse specification is still supported with
+ the "--filter=sparse:oid=<blob>" option.
+
UI, Workflows & Features
* "git checkout --no-overlay" can be used to trigger a new mode of
* The command line completion (in contrib/) has been taught to
complete more subcommand parameters.
+ * The final report from "git bisect" used to show the suspected
+ culprit using a raw "diff-tree", with which there is no output for
+ a merge commit. This has been updated to use a more modern and
+ human readable output that still is concise enough.
+
+ * "git rebase --rebase-merges" replaces its old "--preserve-merges"
+ option; the latter is now marked as deprecated.
+
+ * Error message given while cloning with --recurse-submodules has
+ been updated.
+
+ * The completion helper code now pays attention to repository-local
+ configuration (when available), which allows --list-cmds to honour
+ a repository specific setting of completion.commands, for example.
+
+ * "git mergetool" learned to offer Sublime Merge (smerge) as one of
+ its backends.
+
+ * A new hook "post-index-change" is called when the on-disk index
+ file changes, which can help e.g. a virtualized working tree
+ implementation.
+
+ * "git difftool" can now run outside a repository.
+
+ * "git checkout -m <other>" was about carrying the differences
+ between HEAD and the working-tree files forward while checking out
+ another branch, and ignored the differences between HEAD and the
+ index. The command has been taught to abort when the index and the
+ HEAD are different.
+
+ * A progress indicator has been added to the "index-pack" step, which
+ often makes users wait for completion during "git clone".
+
+ * "git submodule" learns "set-branch" subcommand that allows the
+ submodule.*.branch settings to be modified.
+
+ * "git merge-recursive" backend recently learned a new heuristics to
+ infer file movement based on how other files in the same directory
+ moved. As this is inherently less robust heuristics than the one
+ based on the content similarity of the file itself (rather than
+ based on what its neighbours are doing), it sometimes gives an
+ outcome unexpected by the end users. This has been toned down to
+ leave the renamed paths in higher/conflicted stages in the index so
+ that the user can examine and confirm the result.
+
+ * "git tag" learned to give an advice suggesting it might be a
+ mistake when creating an annotated or signed tag that points at
+ another tag.
+
+ * The "git pack-objects" command learned to report the number of
+ objects it packed via the trace2 mechanism.
+
+ * The list of conflicted paths shown in the editor while concluding a
+ conflicted merge was shown above the scissors line when the
+ clean-up mode is set to "scissors", even though it was commented
+ out just like the list of updated paths and other information to
+ help the user explain the merge better.
+
+ * The trace2 tracing facility learned to auto-generate a filename
+ when told to log to a directory.
+
+ * "git clone" learned a new --server-option option when talking over
+ the protocol version 2.
+
+ * The connectivity bitmaps are created by default in bare
+ repositories now; also the pathname hash-cache is created by
+ default to avoid making crappy deltas when repacking.
+
+ * "git branch new A...B" and "git checkout -b new A...B" have been
+ taught that in their contexts, the notation A...B means "the merge
+ base between these two commits", just like "git checkout A...B"
+ detaches HEAD at that commit.
+
+ * Update "git difftool" and "git mergetool" so that the combinations
+ of {diff,merge}.{tool,guitool} configuration variables serve as
+ fallback settings of each other in a sensible order.
+
+ * The "--dir-diff" mode of "git difftool" is not useful in "--no-index"
+ mode; they are now explicitly marked as mutually incompatible.
+
Performance, Internal Implementation, Development Support etc.
* "git prune" has been taught to take advantage of reachability
bitmap when able.
+ * The command line parser of "git commit-tree" has been rewritten to
+ use the parse-options API.
+
+ * Suggest GitGitGadget instead of submitGit as a way to submit
+ patches based on GitHub PR to us.
+
+ * The test framework has been updated to help developers by making it
+ easier to run most of the tests under different versions of
+ over-the-wire protocols.
+
+ * Dev support update to make it easier to compare two formatted
+ results from our documentation.
+
+ * The scripted "git rebase" implementation has been retired.
+
+ * "git multi-pack-index verify" did not scale well with the number of
+ packfiles, which is being improved.
+
+ * "git stash" has been rewritten in C.
+
+ * The "check-docs" Makefile target to support developers has been
+ updated.
+
+ * The tests have been updated not to rely on the abbreviated option
+ names the parse-options API offers, to protect us from an
+ abbreviated form of an option that used to be unique within the
+ command getting non-unique when a new option that share the same
+ prefix is added.
+
+ * The scripted version of "git rebase -i" wrote and rewrote the todo
+ list many times during a single step of its operation, and the
+ recent C-rewrite made a faithful conversion of the logic to C. The
+ implementation has been updated to carry necessary information
+ around in-core to avoid rewriting the same file over and over
+ unnecessarily.
+
+ * Test framework update to more robustly clean up leftover files and
+ processes after tests are done.
+
+ * Conversion from unsigned char[20] to struct object_id continues.
+
+ * While running "git diff" in a lazy clone, we can upfront know which
+ missing blobs we will need, instead of waiting for the on-demand
+ machinery to discover them one by one. The code learned to aim to
+ achieve better performance by batching the request for these
+ promised blobs.
+
+ * During an initial "git clone --depth=..." partial clone, it is
+ pointless to spend cycles for a large portion of the connectivity
+ check that enumerates and skips promisor objects (which by
+ definition is all objects fetched from the other side). This has
+ been optimized out.
+
+ * Mechanically and systematically drop "extern" from function
+ declaration.
+
+ * The script to aggregate perf result unconditionally depended on
+ libjson-perl even though it did not have to, which has been
+ corrected.
+
+ * The internal implementation of "git rebase -i" has been updated to
+ avoid forking a separate "rebase--interactive" process.
+
+ * Allow DEP and ASLR for Windows build to for security hardening.
+
+ * Performance test framework has been broken and measured the version
+ of Git that happens to be on $PATH, not the specified one to
+ measure, for a while, which has been corrected.
+
+ * Optionally "make coccicheck" can feed multiple source files to
+ spatch, gaining performance while spending more memory.
+
+ * Attempt to use an abbreviated option in "git clone --recurs" is
+ responded by a request to disambiguate between --recursive and
+ --recurse-submodules, which is bad because these two are synonyms.
+ The parse-options API has been extended to define such synonyms
+ more easily and not produce an unnecessary failure.
+
+ * A pair of private functions in http.c that had names similar to
+ fread/fwrite did not return the number of elements, which was found
+ to be confusing.
+
+ * Update collision-detecting SHA-1 code to build properly on HP-UX.
+
Fixes since v2.21
-----------------
ETAGS on.
(merge 92b88eba9f js/find-lib-h-with-ls-files-when-possible later to maint).
+ * "git rebase" that was reimplemented in C did not set ORIG_HEAD
+ correctly, which has been corrected.
+ (merge cbd29ead92 js/rebase-orig-head-fix later to maint).
+
+ * Dev support.
+ (merge f545737144 js/stress-test-ui-tweak later to maint).
+
+ * CFLAGS now can be tweaked when invoking Make while using
+ DEVELOPER=YesPlease; this did not work well before.
+ (merge 6d5d4b4e93 ab/makefile-help-devs-more later to maint).
+
+ * "git fsck --connectivity-only" omits computation necessary to sift
+ the objects that are not reachable from any of the refs into
+ unreachable and dangling. This is now enabled when dangling
+ objects are requested (which is done by default, but can be
+ overridden with the "--no-dangling" option).
+ (merge 8d8c2a5aef jk/fsck-doc later to maint).
+
+ * On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX),
+ the upload-pack that runs on the other end that hangs up after
+ detecting an error could cause "git fetch" to die with a signal,
+ which led to a flaky test. "git fetch" now ignores SIGPIPE during
+ the network portion of its operation (this is not a problem as we
+ check the return status from our write(2)s).
+ (merge 143588949c jk/no-sigpipe-during-network-transport later to maint).
+
+ * A recent update broke "is this object available to us?" check for
+ well-known objects like an empty tree (which should yield "yes",
+ even when there is no on-disk object for an empty tree), which has
+ been corrected.
+ (merge f06ab027ef jk/virtual-objects-do-exist later to maint).
+
+ * The setup code has been cleaned up to avoid leaks around the
+ repository_format structure.
+ (merge e8805af1c3 ma/clear-repository-format later to maint).
+
+ * "git config --type=color ..." is meant to replace "git config --get-color"
+ but there is a slight difference that wasn't documented, which is
+ now fixed.
+ (merge cd8e7593b9 jk/config-type-color-ends-with-lf later to maint).
+
+ * When the "clean" filter can reduce the size of a huge file in the
+ working tree down to a small "token" (a la Git LFS), there is no
+ point in allocating a huge scratch area upfront, but the buffer is
+ sized based on the original file size. The convert mechanism now
+ allocates very minimum and reallocates as it receives the output
+ from the clean filter process.
+ (merge 02156ab031 jh/resize-convert-scratch-buffer later to maint).
+
+ * "git rebase" uses the refs/rewritten/ hierarchy to store its
+ intermediate states, which inherently makes the hierarchy per
+ worktree, but it didn't quite work well.
+ (merge b9317d55a3 nd/rewritten-ref-is-per-worktree later to maint).
+
+ * "git log -L<from>,<to>:<path>" with "-s" did not suppress the patch
+ output as it should. This has been corrected.
+ (merge 05314efaea jk/line-log-with-patch later to maint).
+
+ * "git worktree add" used to do a "find an available name with stat
+ and then mkdir", which is race-prone. This has been fixed by using
+ mkdir and reacting to EEXIST in a loop.
+ (merge 7af01f2367 ms/worktree-add-atomic-mkdir later to maint).
+
+ * Build update for SHA-1 with collision detection.
+ (merge 07a20f569b jk/sha1dc later to maint).
+
+ * Build procedure has been fixed around use of asciidoctor instead of
+ asciidoc.
+ (merge 185f9a0ea0 ma/asciidoctor-fixes later to maint).
+
+ * remote-http transport did not anonymize URLs reported in its error
+ messages at places.
+ (merge c1284b21f2 js/anonymize-remote-curl-diag later to maint).
+
+ * Error messages given from the http transport have been updated so
+ that they can be localized.
+ (merge ed8b4132c8 js/remote-curl-i18n later to maint).
+
+ * "git init" forgot to read platform-specific repository
+ configuration, which made Windows port to ignore settings of
+ core.hidedotfiles, for example.
+
+ * A corner-case object name ambiguity while the sequencer machinery
+ is working (e.g. "rebase -i -x") has been fixed.
+
+ * "git format-patch" did not diagnose an error while opening the
+ output file for the cover-letter, which has been corrected.
+ (merge 2fe95f494c jc/format-patch-error-check later to maint).
+
+ * "git checkout -f <branch>" while the index has an unmerged path
+ incorrectly left some paths in an unmerged state, which has been
+ corrected.
+
+ * A corner case bug in the refs API has been corrected.
+ (merge d3322eb28b jk/refs-double-abort later to maint).
+
+ * Unicode update.
+ (merge 584b62c37b bb/unicode-12 later to maint).
+
+ * dumb-http walker has been updated to share more error recovery
+ strategy with the normal codepath.
+
+ * A buglet in configuration parser has been fixed.
+ (merge 19e7fdaa58 nd/include-if-wildmatch later to maint).
+
+ * The documentation for "git read-tree --reset -u" has been updated.
+ (merge b5a0bd694c nd/read-tree-reset-doc later to maint).
+
+ * Code clean-up around a much-less-important-than-it-used-to-be
+ update_server_info() function.
+ (merge b3223761c8 jk/server-info-rabbit-hole later to maint).
+
+ * The message given when "git commit -a <paths>" errors out has been
+ updated.
+ (merge 5a1dbd48bc nd/commit-a-with-paths-msg-update later to maint).
+
+ * "git cherry-pick --options A..B", after giving control back to the
+ user to ask help resolving a conflicted step, did not honor the
+ options it originally received, which has been corrected.
+
+ * Various glitches in "git gc" around reflog handling have been fixed.
+
+ * The code to read from commit-graph file has been cleanup with more
+ careful error checking before using data read from it.
+
+ * Performance fix around "git fetch" that grabs many refs.
+ (merge b764300912 jt/fetch-pack-wanted-refs-optim later to maint).
+
+ * Protocol v2 support in "git fetch-pack" of shallow clones has been
+ corrected.
+
+ * Performance fix around "git blame", especially in a linear history
+ (which is the norm we should optimize for).
+ (merge f892014943 dk/blame-keep-origin-blob later to maint).
+
+ * Performance fix for "rev-list --parents -- pathspec".
+ (merge 8320b1dbe7 jk/revision-rewritten-parents-in-prio-queue later to maint).
+
+ * Updating the display with progress message has been cleaned up to
+ deal better with overlong messages.
+ (merge 545dc345eb sg/overlong-progress-fix later to maint).
+
+ * "git blame -- path" in a non-bare repository starts blaming from
+ the working tree, and the same command in a bare repository errors
+ out because there is no working tree by definition. The command
+ has been taught to instead start blaming from the commit at HEAD,
+ which is more useful.
+ (merge a544fb08f8 sg/blame-in-bare-start-at-head later to maint).
+
+ * An underallocation in the code to read the untracked cache
+ extension has been corrected.
+ (merge 3a7b45a623 js/untracked-cache-allocfix later to maint).
+
+ * The code is updated to check the result of memory allocation before
+ it is used in more places, by using xmalloc and/or xcalloc calls.
+ (merge 999b951b28 jk/xmalloc later to maint).
+
+ * The GETTEXT_POISON test option has been quite broken ever since it
+ was made runtime-tunable, which has been fixed.
+ (merge f88b9cb603 jc/gettext-test-fix later to maint).
+
+ * Test fix on APFS that is incapable of store paths in Latin-1.
+ (merge 3889149619 js/iso8895-test-on-apfs later to maint).
+
+ * "git submodule foreach <command> --quiet" did not pass the option
+ down correctly, which has been corrected.
+ (merge a282f5a906 nd/submodule-foreach-quiet later to maint).
+
+ * "git send-email" has been taught to use quoted-printable when the
+ payload contains carriage-return. The use of the mechanism is in
+ line with the design originally added the codepath that chooses QP
+ when the payload has overly long lines.
+ (merge 74d76a1701 bc/send-email-qp-cr later to maint).
+
+ * The recently added feature to add addresses that are on
+ anything-by: trailers in 'git send-email' was found to be way too
+ eager and considered nonsense strings as if they can be legitimate
+ beginning of *-by: trailer. This has been tightened.
+
+ * Builds with gettext broke on recent macOS w/ Homebrew, which
+ seems to have stopped including from /usr/local/include; this
+ has been corrected.
+ (merge 92a1377a2a js/macos-gettext-build later to maint).
+
+ * Running "git add" on a repository created inside the current
+ repository is an explicit indication that the user wants to add it
+ as a submodule, but when the HEAD of the inner repository is on an
+ unborn branch, it cannot be added as a submodule. Worse, the files
+ in its working tree can be added as if they are a part of the outer
+ repository, which is not what the user wants. These problems are
+ being addressed.
+ (merge f937bc2f86 km/empty-repo-is-still-a-repo later to maint).
+
+ * "git cherry-pick" run with the "-x" or the "--signoff" option used
+ to (and more importantly, ought to) clean up the commit log message
+ with the --cleanup=space option by default, but this has been
+ broken since late 2017. This has been fixed.
+
+ * When given a tag that points at a commit-ish, "git replace --graft"
+ failed to peel the tag before writing a replace ref, which did not
+ make sense because the old graft mechanism the feature wants to
+ mimic only allowed to replace one commit object with another.
+ This has been fixed.
+ (merge ee521ec4cb cc/replace-graft-peel-tags later to maint).
+
+ * Code tightening against a "wrong" object appearing where an object
+ of a different type is expected, instead of blindly assuming that
+ the connection between objects are correctly made.
+ (merge 97dd512af7 tb/unexpected later to maint).
+
+ * An earlier update for MinGW and Cygwin accidentally broke MSVC build,
+ which has been fixed.
+ (merge 22c3634c0f ss/msvc-path-utils-fix later to maint).
+
+ * %(push:track) token used in the --format option to "git
+ for-each-ref" and friends was not showing the right branch, which
+ has been fixed.
+ (merge c646d0934e dr/ref-filter-push-track-fix later to maint).
+
+ * "make check-docs", "git help -a", etc. did not account for cases
+ where a particular build may deliberately omit some subcommands,
+ which has been corrected.
+
+ * The logic to tell if a Git repository has a working tree protects
+ "git branch -D" from removing the branch that is currently checked
+ out by mistake. The implementation of this logic was broken for
+ repositories with unusual name, which unfortunately is the norm for
+ submodules these days. This has been fixed.
+ (merge f3534c98e4 jt/submodule-repo-is-with-worktree later to maint).
+
+ * AIX shared the same build issues with other BSDs around fileno(fp),
+ which has been corrected.
+ (merge ee662bf5c6 cc/aix-has-fileno-as-a-macro later to maint).
+
+ * The autoconf generated configure script failed to use the right
+ gettext() implementations from -libintl by ignoring useless stub
+ implementations shipped in some C library, which has been
+ corrected.
+ (merge b71e56a683 vk/autoconf-gettext later to maint).
+
+ * Fix index-pack perf test so that the repeated invocations always
+ run in an empty repository, which emulates the initial clone
+ situation better.
+ (merge 775c71e16d jk/p5302-avoid-collision-check-cost later to maint).
+
+ * A "ls-files" that emulates "find" to enumerate files in the working
+ tree resulted in duplicated Makefile rules that caused the build to
+ issue an unnecessary warning during a trial build after merge
+ conflicts are resolved in working tree *.h files but before the
+ resolved results are added to the index. This has been corrected.
+
+ * "git cherry-pick" (and "revert" that shares the same runtime engine)
+ that deals with multiple commits got confused when the final step
+ gets stopped with a conflict and the user concluded the sequence
+ with "git commit". Attempt to fix it by cleaning up the state
+ files used by these commands in such a situation.
+ (merge 4a72486de9 pw/clean-sequencer-state-upon-final-commit later to maint).
+
+ * On a filesystem like HFS+, the names of the refs stored as filesystem
+ entities may become different from what the end-user expects, just
+ like files in the working tree get "renamed". Work around the
+ mismatch by paying attention to the core.precomposeUnicode
+ configuration.
+ (merge 8e712ef6fc en/unicode-in-refnames later to maint).
+
+ * The code to generate the multi-pack idx file was not prepared to
+ see too many packfiles and ran out of open file descriptor, which
+ has been corrected.
+
+ * To run tests for Git SVN, our scripts for CI used to install the
+ git-svn package (in the hope that it would bring in the right
+ dependencies). This has been updated to install the more direct
+ dependency, namely, libsvn-perl.
+ (merge db864306cf sg/ci-libsvn-perl later to maint).
+
+ * "git cvsexportcommit" running on msys did not expect cvsnt showed
+ "cvs status" output with CRLF line endings.
+
+ * The fsmonitor interface got out of sync after the in-core index
+ file gets discarded, which has been corrected.
+ (merge 398a3b0899 js/fsmonitor-refresh-after-discarding-index later to maint).
+
+ * "git status" did not know that the "label" instruction in the
+ todo-list "rebase -i -r" uses should not be shown as a hex object
+ name.
+
+ * A prerequisite check in the test suite to see if a working jgit is
+ available was made more robust.
+ (merge abd0f28983 tz/test-lib-check-working-jgit later to maint).
+
+ * The codepath to parse :<path> that obtains the object name for an
+ indexed object has been made more robust.
+
* Code cleanup, docfix, build fix, etc.
(merge 11f470aee7 jc/test-yes-doc later to maint).
(merge 90503a240b js/doc-symref-in-proto-v1 later to maint).
(merge 716a5af812 rd/gc-prune-doc-fix later to maint).
(merge 50b206371d js/untravis-windows later to maint).
(merge dbf47215e3 js/rebase-recreate-merge later to maint).
+ (merge 56cb2d30f8 dl/reset-doc-no-wrt-abbrev later to maint).
+ (merge 64eca306a2 ja/dir-rename-doc-markup-fix later to maint).
+ (merge af91b0230c dl/ignore-docs later to maint).
+ (merge 59a06e947b ra/t3600-test-path-funcs later to maint).
+ (merge e041d0781b ar/t4150-remove-cruft later to maint).
+ (merge 8d75a1d183 ma/asciidoctor-fixes-more later to maint).
+ (merge 74cc547b0f mh/pack-protocol-doc-fix later to maint).
+ (merge ed31851fa6 ab/doc-misc-typofixes later to maint).
+ (merge a7256debd4 nd/checkout-m-doc-update later to maint).
+ (merge 3a9e1ad78d jt/t5551-protocol-v2-does-not-have-half-auth later to maint).
+ (merge 0b918b75af sg/t5318-cleanup later to maint).
+ (merge 68ed71b53c cb/doco-mono later to maint).
+ (merge a34dca2451 nd/interpret-trailers-docfix later to maint).
+ (merge cf7b857a77 en/fast-import-parsing-fix later to maint).
+ (merge fe61ccbc35 po/rerere-doc-fmt later to maint).
+ (merge ffea0248bf po/describe-not-necessarily-7 later to maint).
+ (merge 7cb7283adb tg/ls-files-debug-format-fix later to maint).
+ (merge f64a21bd82 tz/doc-apostrophe-no-longer-needed later to maint).
+ (merge dbe7b41019 js/t3301-unbreak-notes-test later to maint).
+ (merge d8083e4180 km/t3000-retitle later to maint).
+ (merge 9e4cbccbd7 tz/git-svn-doc-markup-fix later to maint).
+ (merge da9ca955a7 jk/ls-files-doc-markup-fix later to maint).
+ (merge 6804ba3a58 cw/diff-highlight later to maint).
+ (merge 1a8787144d nd/submodule-helper-incomplete-line-fix later to maint).
+ (merge d9ef573837 jk/apache-lsan later to maint).
+ (merge c871fbee2b js/t6500-use-windows-pid-on-mingw later to maint).
+ (merge ce4c7bfc90 bl/t4253-exit-code-from-format-patch later to maint).
+ (merge 397a46db78 js/t5580-unc-alternate-test later to maint).
+ (merge d4907720a2 cm/notes-comment-fix later to maint).
+ (merge 9dde06de13 cb/http-push-null-in-message-fix later to maint).
+ (merge 4c785c0edc js/rebase-config-bitfix later to maint).
+ (merge 8e9fe16c87 es/doc-gitsubmodules-markup later to maint).