Documentation/RelNotes/2.39.0.txt

Git v2.39 Release Notes
=======================

UI, Workflows & Features
------------------------

 * "git grep" learned to expand the sparse-index more lazily and on
   demand in a sparse checkout.

 * By default, use of fsmonitor on a repository on networked
   filesystem is disabled. Add knobs to make it workable on macOS.

 * After checking out a "branch" that is a symbolic-ref that points at
   another branch, "git symbolic-ref HEAD" reports the underlying
   branch, not the symbolic-ref the user gave checkout as argument.
   The command learned the "--no-recurse" option to stop after
   dereferencing a symbolic-ref only once.

 * "git branch --edit-description @{-1}" is now a way to edit branch
   description of the branch you were on before switching to the
   current branch.

 * "git merge-tree --stdin" is a new way to request a series of merges
   and report the merge results.

 * "git shortlog" learned to group by the "format" string.

 * A new "--include-whitespace" option is added to "git patch-id", and
   existing bugs in the internal patch-id logic that did not match
   what "git patch-id" produces have been corrected.

 * Enable gc.cruftpacks by default for those who opt into
   feature.experimental setting.

 * "git repack" learns to send cruft objects out of the way into
   packfiles outside the repository.

Performance, Internal Implementation, Development Support etc.
--------------------------------------------------------------

 * With a bit of header twiddling, use the native regexp library on
   macOS instead of the compat/ one.

 * Prepare for GNU [ef]grep that throw warning of their uses.

 * Sources related to fuzz testing have been moved down to their own
   directory.

 * Most credential helpers ignored unknown entries in a credential
   description, but a few died upon seeing them.  The latter were
   taught to ignore them, too

 * "scalar unregister" in a repository that is already been
   unregistered reported an error.

 * Remove error detection from a function that fetches from promisor
   remotes, and make it die when such a fetch fails to bring all the
   requested objects, to give an early failure to various operations.

 * Update CodingGuidelines to clarify what features to use and avoid
   in C99.

 * Avoid false-positive from LSan whose assumption may be broken with
   higher optimization levels.

 * Enable address and undefined sanitizer tasks at GitHub Actions CI.

 * More UNUSED annotation to help using -Wunused option with the
   compiler.
   (merge 4b992f0a24 jk/unused-anno-more later to maint).

 * Rewrite a deep recursion in the skipping negotiator to use a loop
   with on-heap prio queue to avoid stack wastage.

 * Add documentation for message IDs in fsck error messages.

 * Define the logical elements of a "bundle list", data structure to
   store them in-core, format to transfer them, and code to parse
   them.

 * The role the security mailing list plays in an embargoed release
   has been documented.

 * Two new facilities, "timer" and "counter", are introduced to the
   trace2 API.

 * Code simplification by using strvec_pushf() instead of building an
   argument in a separate strbuf.

 * Make sure generated dependency file is stably sorted to help
   developers debugging their build issues.

 * The glossary entries for "commit-graph file" and "reachability
   bitmap" have been added.

 * Various tests exercising the transfer.credentialsInUrl
   configuration are taught to avoid making requests which require
   resolving localhost to reduce CI-flakiness.

 * A redundant diagnostic message is dropped from test_path_is_missing().

 * Simplify the run-command API.

 * Update the actions/github-script dependency in CI to avoid a
   deprecation warning.

 * Progress on being able to initialize a rev_info struct with a
   macro.

 * Add trace2 counters to the region to clear skip worktree bits in a
   sparse checkout.

 * Modernize test script to avoid "test -f" and friends.

 * Avoid calling 'cache_tree_update()' when doing so would be
   redundant.

 * Update the credential-cache documentation to provide a more
   realistic example.

 * Makefile comments updates and reordering to clarify knobs used to
   choose SHA implementations.

 * A design document for sparse-checkout's future directions has been
   added.

Fixes since v2.38
-----------------

 * The codepath that reads from the index v4 had unaligned memory
   accesses, which has been corrected.

 * Fix messages incorrectly marked for translation.

 * "git fsck" failed to release contents of tree objects already used
   from the memory, which has been fixed.

 * "git clone" did not like to see the "--bare" and the "--origin"
   options used together without a good reason.

 * "git remote rename" failed to rename a remote without fetch
   refspec, which has been corrected.

 * Documentation on various Boolean GIT_* environment variables have
   been clarified.

 * "git rebase -i" can mistakenly attempt to apply a fixup to a commit
   itself, which has been corrected.

 * "git multi-pack-index repack/expire" used to repack unreachable
   cruft into a new pack, which have been corrected.

 * In read-only repositories, "git merge-tree" tried to come up with a
   merge result tree object, which it failed (which is not wrong) and
   led to a segfault (which is bad), which has been corrected.

 * Force C locale while running tests around httpd to make sure we can
   find expected error messages in the log.

 * Fix a logic in "mailinfo -b" that miscomputed the length of a
   substring, which lead to an out-of-bounds access.

 * The codepath to sign learned to report errors when it fails to read
   from "ssh-keygen".

 * Code clean-up that results in plugging a leak.

 * "GIT_EDITOR=: git branch --edit-description" resulted in failure,
   which has been corrected.

 * The code to clean temporary object directories (used for
   quarantine) tried to remove them inside its signal handler, which
   was a no-no.

 * Update comment in the Makefile about the RUNTIME_PREFIX config knob.

 * Clarify that "the sentence after <area>: prefix does not begin with
   a capital letter" rule applies only to the commit title.

 * "git branch --edit-description" on an unborh branch misleadingly
   said that no such branch exists, which has been corrected.

 * Work around older clang that warns against C99 zero initialization
   syntax for struct.

 * Giving "--invert-grep" and "--all-match" without "--grep" to the
   "git log" command resulted in an attempt to access grep pattern
   expression structure that has not been allocated, which has been
   corrected.
   (merge db84376f98 ab/grep-simplify-extended-expression later to maint).

 * "git diff rev^!" did not show combined diff to go to the rev from
   its parents.
   (merge a79c6b6081 rs/diff-caret-bang-with-parents later to maint).

 * Allow configuration files in "protected" scopes to include other
   configuration files.
   (merge ecec57b3c9 gc/bare-repo-discovery later to maint).

 * Give a bit more diversity to macOS CI by using sha1dc in one of the
   jobs (the other one tests Apple Common Crypto).
   (merge 1ad5c3df35 jc/ci-osx-with-sha1dc later to maint).

 * A bugfix with tracing support in midx codepath
   (merge e9c3839944 tb/midx-bitmap-selection-fix later to maint).

 * When geometric repacking feature is in use together with the
   --pack-kept-objects option, we lost packs marked with .keep files.
   (merge 197443e80a tb/save-keep-pack-during-geometric-repack later to maint).

 * Move a global variable added as a hack during regression fixes to
   its proper place in the API.
   (merge 0b0ab95f17 ab/run-hook-api-cleanup later to maint).

 * Update to build procedure with VS using CMake/CTest.
   (merge c858750b41 js/cmake-updates later to maint).

 * The short-help text shown by "git cmd -h" and the synopsis text
   shown at the beginning of "git help cmd" have been made more
   consistent.

 * When creating a multi-pack bitmap, remove per-pack bitmap files
   unconditionally as they will never be consulted.
   (merge 55d902cd61 tb/remove-unused-pack-bitmap later to maint).

 * Fix a longstanding syntax error in Git.pm error codepath.

 * "git diff --stat" etc. were invented back when everything was ASCII
   and strlen() was a way to measure the display width of a string;
   adjust them to compute the display width assuming UTF-8 pathnames.
   (merge ce8529b2bb tb/diffstat-with-utf8-strwidth later to maint).

 * "git branch --edit-description" can exit with status -1 which is
   not a good practice; it learned to use 1 as everybody else instead.

 * "git apply" limits its input to a bit less than 1 GiB.

 * Merging a branch with directory renames into a branch that changes
   the directory to a symlink was mishandled by the ort merge
   strategy, which has been corrected.

 * A bugfix to "git subtree" in its split and merge features.

 * Fix some bugs in the reflog messages when rebasing and changes the
   reflog messages of "rebase --apply" to match "rebase --merge" with
   the aim of making the reflog easier to parse.

 * "git rebase --keep-base" used to discard the commits that are
   already cherry-picked to the upstream, even when "keep-base" meant
   that the base, on top of which the history is being rebuilt, does
   not yet include these cherry-picked commits.  The --keep-base
   option now implies --reapply-cherry-picks and --no-fork-point
   options.

 * The way "git repack" creared temporary files when it received a
   signal was prone to deadlocking, which has been corrected.

 * Various tests exercising the transfer.credentialsInUrl
   configuration are taught to avoid making requests which require
   resolving localhost to reduce CI-flakiness.

 * The adjust_shared_perm() helper function learned to refrain from
   setting the "g+s" bit on directories when it is not necessary.

 * "git archive" mistakenly complained twice about a missing
   executable, which has been corrected.

 * Fix a bug where `git branch -d` did not work on an orphaned HEAD.

 * `git rebase --update-refs` would delete references when all
   `update-ref` commands in the sequencer were removed, which has been
   corrected.

 * Other code cleanup, docfix, build fix, etc.
   (merge 413bc6d20a ds/cmd-main-reorder later to maint).
   (merge 8d2863e4ed nw/t1002-cleanup later to maint).