Documentation/RelNotes/2.39.0.txt - jrn/git - Git at Google

 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.

  * 'scalar reconfigure -a' is taught to automatically remove
    scalar.repo entires which no longer exist.

  * Redact headers from cURL's h2h3 module in GIT_CURL_VERBOSE and
    others.

  * 'git maintenance register' is taught to write configuration to an
    arbitrary path, and 'git for-each-repo' is taught to expand tilde
    characters in paths.

  * When creating new notes, the template used to get a stray empty
    newline, which has been removed.

  * "git receive-pack" used to use all the local refs as the boundary for
    checking connectivity of the data "git push" sent, but now it uses
    only the refs that it advertised to the pusher. In a repository with
    the .hideRefs configuration, this reduces the resources needed to
    perform the check.

  * With '--recurse-submodules=on-demand', all submodules are
    recursively pushed.


 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.

  * Teach chainlint.pl to annotate the original test definition instead
    of the token stream.

  * "make coccicheck" is time consuming. It has been made to run more
    incrementally.

  * `parse_object()` has been hardened to check for the existence of a
    suspected blob object.

  * The build procedure has been adjusted to GNUmake version 4.4, which
    made some changes to how pattern rule with multiple targets are
    handled.


 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 unborn 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" created 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.

  * Fix a regression in the bisect-helper which mistakenly treats
    arguments to the command given to 'git bisect run' as arguments to
    the helper.

  * Correct an error where `git rebase` would mistakenly use a branch or
    tag named "refs/rewritten/xyz" when missing a rebase label.

  * Assorted fixes of parsing end-user input as integers.
    (merge 14770cf0de pw/config-int-parse-fixes later to maint).

  * "git prune" may try to iterate over .git/objects/pack for trash
    files to remove in it, and loudly fail when the directory is
    missing, which is not necessary.  The command has been taught to
    ignore such a failure.
    (merge 6974765352 ew/prune-with-missing-objects-pack later to maint).

  * Add one more candidate directory that may house httpd modules while
    running tests.
    (merge 1c7dc23d41 es/locate-httpd-module-location-in-test later to maint).

  * A handful of leaks in the line-log machinery have been plugged.

  * The format of a line in /proc/cpuinfo that describes a CPU on s390x
    looked different from everybody else, and the code in chainlint.pl
    failed to parse it.
    (merge 1f51b77f4f ah/chainlint-cpuinfo-parse-fix later to maint).

  * Adjust the GitHub CI to newer ubuntu release.
    (merge 0d3507f3e7 jx/ci-ubuntu-fix later to maint).

  * Other code cleanup, docfix, build fix, etc.
    (merge 413bc6d20a ds/cmd-main-reorder later to maint).
    (merge 8d2863e4ed nw/t1002-cleanup later to maint).
    (merge 7c2dc122f9 rs/list-objects-filter-leakfix later to maint).
    (merge 288fcb1c94 zk/push-use-bitmaps later to maint).
    (merge 42db324c0f km/merge-recursive-typofix later to maint).
	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.

	* 'scalar reconfigure -a' is taught to automatically remove
	scalar.repo entires which no longer exist.

	* Redact headers from cURL's h2h3 module in GIT_CURL_VERBOSE and
	others.

	* 'git maintenance register' is taught to write configuration to an
	arbitrary path, and 'git for-each-repo' is taught to expand tilde
	characters in paths.

	* When creating new notes, the template used to get a stray empty
	newline, which has been removed.

	* "git receive-pack" used to use all the local refs as the boundary for
	checking connectivity of the data "git push" sent, but now it uses
	only the refs that it advertised to the pusher. In a repository with
	the .hideRefs configuration, this reduces the resources needed to
	perform the check.

	* With '--recurse-submodules=on-demand', all submodules are
	recursively pushed.


	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.

	* Teach chainlint.pl to annotate the original test definition instead
	of the token stream.

	* "make coccicheck" is time consuming. It has been made to run more
	incrementally.

	* `parse_object()` has been hardened to check for the existence of a
	suspected blob object.

	* The build procedure has been adjusted to GNUmake version 4.4, which
	made some changes to how pattern rule with multiple targets are
	handled.


	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 unborn 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" created 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.

	* Fix a regression in the bisect-helper which mistakenly treats
	arguments to the command given to 'git bisect run' as arguments to
	the helper.

	* Correct an error where `git rebase` would mistakenly use a branch or
	tag named "refs/rewritten/xyz" when missing a rebase label.

	* Assorted fixes of parsing end-user input as integers.
	(merge 14770cf0de pw/config-int-parse-fixes later to maint).

	* "git prune" may try to iterate over .git/objects/pack for trash
	files to remove in it, and loudly fail when the directory is
	missing, which is not necessary. The command has been taught to
	ignore such a failure.
	(merge 6974765352 ew/prune-with-missing-objects-pack later to maint).

	* Add one more candidate directory that may house httpd modules while
	running tests.
	(merge 1c7dc23d41 es/locate-httpd-module-location-in-test later to maint).

	* A handful of leaks in the line-log machinery have been plugged.

	* The format of a line in /proc/cpuinfo that describes a CPU on s390x
	looked different from everybody else, and the code in chainlint.pl
	failed to parse it.
	(merge 1f51b77f4f ah/chainlint-cpuinfo-parse-fix later to maint).

	* Adjust the GitHub CI to newer ubuntu release.
	(merge 0d3507f3e7 jx/ci-ubuntu-fix later to maint).

	* Other code cleanup, docfix, build fix, etc.
	(merge 413bc6d20a ds/cmd-main-reorder later to maint).
	(merge 8d2863e4ed nw/t1002-cleanup later to maint).
	(merge 7c2dc122f9 rs/list-objects-filter-leakfix later to maint).
	(merge 288fcb1c94 zk/push-use-bitmaps later to maint).
	(merge 42db324c0f km/merge-recursive-typofix later to maint).