79603 Commits

Author SHA1 Message Date
Junio C Hamano
35d72c8eb9 Merge branch 'kt/http-backend-errors' into next
Some error messages from the http transport layer lacked the
terminating newline, which has been corrected.

* kt/http-backend-errors:
  http-backend: write newlines to stderr when responding with errors
2026-01-13 10:43:40 -08:00
Junio C Hamano
51b666d16e Merge branch 'ps/t1410-cleanup' into next
Test clean-up.

* ps/t1410-cleanup:
  t1410: use test helpers in reflog rewind test
2026-01-13 10:43:40 -08:00
Junio C Hamano
ba6c9deadb Merge branch 'ps/ref-consistency-checks' into next
Update code paths that check data integrity around refs subsystem.

* ps/ref-consistency-checks:
  builtin/fsck: drop `fsck_head_link()`
  builtin/fsck: move generic HEAD check into `refs_fsck()`
  builtin/fsck: move generic object ID checks into `refs_fsck()`
  refs/reftable: introduce generic checks for refs
  refs/reftable: fix consistency checks with worktrees
  refs/reftable: extract function to retrieve backend for worktree
  refs/reftable: adapt includes to become consistent
  refs/files: introduce function to perform normal ref checks
  refs/files: extract generic symref target checks
  fsck: drop unused fields from `struct fsck_ref_report`
  refs/files: perform consistency checks for root refs
  refs/files: improve error handling when verifying symrefs
  refs/files: extract function to check single ref
  refs/files: remove useless indirection
  refs/files: remove `refs_check_dir` parameter
  refs/files: move fsck functions into global scope
  refs/files: simplify iterating through root refs
2026-01-13 10:43:40 -08:00
Junio C Hamano
f2e51d72b8 Merge branch 'tb/macos-iconv-workarounds' into next
The iconv library on macOS fails to correctly handle stateful
ISO/IEC 2022 encoded strings.  Work it around instead of replacing
it wholesale from homebrew.

* tb/macos-iconv-workarounds:
  utf8.c: enable workaround for iconv under macOS 14/15
  utf8.c: prepare workaround for iconv under macOS 14/15
2026-01-13 10:43:40 -08:00
Junio C Hamano
b213ccc8c1 Merge branch 'cs/rebased-subtree-split' into next
The split command in "git subtree" (in contrib/) has been taught to
deal better with rebased history.

* cs/rebased-subtree-split:
  contrib/subtree: detect rewritten subtree commits
2026-01-13 10:43:40 -08:00
Torsten Bögershausen
d281241518 utf8.c: enable workaround for iconv under macOS 14/15
The previous commit introduced a workaround in utf8.c to deal
with broken iconv implementations.

It is enabled when a MacOS version is used that has a buggy
iconv library and there is no external library provided
(and linked against) from neither MacPorts nor Homebrew nor Fink.
For Homebrew, MacPorts and Fink we check if libiconv exist.
Introduce 2 new macros: HAS_GOOD_LIBICONV and NEEDS_GOOD_LIBICONV.

For Homebrew HAS_GOOD_LIBICONV is set when the libiconv directory
exist.
MacPorts can be installed with or without libiconv, so check if
libiconv.dylib exists (which is a softlink)

Fink compiles and installs libiconv by default.
Note that a fresh installation of Fink now defaults to /opt/sw.
Older versions used /sw as default, so leave the check and setting
of BASIC_CFLAGS and BASIC_LDFLAGS as is.
For the new default check for the existance of /opt/sw as well.
Add a check for /opt/sw/lib/libiconv.dylib which sets HAS_GOOD_LIBICONV

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 12:00:39 -08:00
Torsten Bögershausen
d0cec08d70 utf8.c: prepare workaround for iconv under macOS 14/15
MacOS14 (Sonoma) has started to ship an iconv library with bugs.
The same bugs exists even in MacOS 15 (Sequoia)

A bug report running the Git test suite says:

three tests of t3900 fail on macOS 26.1 for me:

  not ok 17 - ISO-2022-JP should be shown in UTF-8 now
  not ok 25 - ISO-2022-JP should be shown in UTF-8 now
  not ok 38 - commit --fixup into ISO-2022-JP from UTF-8

Here's the verbose output of the first one:

=================
expecting success of 3900.17 'ISO-2022-JP should be shown in UTF-8 now':
                compare_with ISO-2022-JP "$TEST_DIRECTORY"/t3900/2-UTF-8.txt

 --- /Users/x/src/git/t/t3900/2-UTF-8.txt 2024-10-01 19:43:24.605230684 +0000
 +++ current     2025-12-08 21:52:45.786161909 +0000
@@ -1,5 +1,5 @@
 はれひほふ

 しているのが、いるので。
 -濱浜ほれぷりぽれまびぐりろへ。
 +濱浜ほれぷりぽれまび$0$j$m$X!#
not ok 17 - ISO-2022-JP should be shown in UTF-8 now
1..17
=================

compare_with runs git show to display a commit message, which in this
case here was encoded using ISO-2022-JP and is supposed to be reencoded
to UTF-8, but git show only does that half-way -- the "$0$j$m$X!#" part
is from the original ISO-2022-JP representation.

That botched conversion is done by utf8.c::reencode_string_iconv().  It
calls iconv(3) to do the actual work, initially with an output buffer of
the same size as the input.  If the output needs more space the function
enlarges the buffer and calls iconv(3) again.

iconv(3) won't tell us how much space it needs, but it will report what
part it already managed to convert, so we can increase the buffer and
continue from there.  ISO-2022-JP has escape codes for switching between
character sets, so it's a stateful encoding.  I guess the iconv(3) on my
machine forgets the state at the end of part one and then messes up part
two.

[end of citation]

Working around the buggy iconv shipped with the OS can be done in
two  ways:
a) Link Git against a different version of iconv
b) Improve the handling when iconv needs a larger output buffer

a) is already done by default when either Fink [1] or MacPorts [2]
   or Homebrew [3] is installed.
b) is implemented here, in case that no fixed iconv is available:
   When the output buffer is too short, increase it (as before)
   and start from scratch (this is new).

This workound needs to be enabled with
'#define ICONV_RESTART_RESET'
and a makefile knob will be added in the next commit

Suggested-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>

[1] https://www.finkproject.org/
[2] https://www.macports.org/
[3] https://brew.sh/

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 12:00:04 -08:00
Patrick Steinhardt
8947da0183 builtin/fsck: drop fsck_head_link()
The function `fsck_head_link()` was historically used to perform a
couple of consistency checks for refs. (Almost) all of these checks have
now been moved into the refs subsystem. There's only a single check
remaining that verifies whether `refs_resolve_ref_unsafe()` returns a
`NULL` pointer. This may happen in a couple of cases:

  - When `refs_is_safe()` declares the ref to be unsafe. We already have
    checks for this as we verify refnames with `check_refname_format()`.

  - When the ref doesn't exist. A repository without "HEAD" is
    completely broken though, and we would notice this error ahead of
    time already.

  - In case the caller passes `RESOLVE_REF_READING` and the ref is a
    symref that doesn't resolve. We don't pass this flag though.

As such, this check doesn't cover anything anymore that isn't already
covered by `refs_fsck()`. Drop it, which also allows us to inline the
call to `refs_resolve_ref_unsafe()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
9727336b31 builtin/fsck: move generic HEAD check into refs_fsck()
Move the check that detects "HEAD" refs that do not point at a branch
into `refs_fsck()`. This follows the same motivation as the preceding
commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
46d611cada builtin/fsck: move generic object ID checks into refs_fsck()
While most of the logic that verifies the consistency of refs is
driven by `refs_fsck()`, we still have a small handful of checks in
`fsck_head_link()`. These checks don't use the git-fsck(1) reporting
infrastructure, and as such it's impossible to for example disable
some of those checks.

One such check detects refs that point to the all-zeroes object ID.
Extract this check into the generic `refs_fsck_ref()` function that is
used by both the "files" and "reftable" backends.

Note that this will cause us to not return an error code from
`fsck_head_link()` anymore in case this error was detected. This is fine
though: the only caller of this function does not check the error code
anyway. To demonstrate this, adapt the function to drop its return value
altogether. The function will be removed in a subsequent commit anyway.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
06d6ead762 refs/reftable: introduce generic checks for refs
In a preceding commit we have extracted generic checks for both direct
and symbolic refs that apply for all backends. Wire up those checks for
the "reftable" backend.

Note that this is done by iterating through all refs manually with the
low-level reftable ref iterator. We explicitly don't want to use the
higher-level iterator that is exposed to users of the reftable backend
as that iterator may swallow for example broken refs.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
9341740bea refs/reftable: fix consistency checks with worktrees
The ref consistency checks are driven via `cmd_refs_verify()`. That
function loops through all worktrees (including the main worktree) and
then checks the ref store for each of them individually. It follows that
the backend is expected to only verify refs that belong to the specified
worktree.

While the "files" backend handles this correctly, the "reftable" backend
doesn't. In fact, it completely ignores the passed worktree and instead
verifies refs of _all_ worktrees. The consequence is that we'll end up
every ref store N times, where N is the number of worktrees.

Or rather, that would be the case if we actually iterated through the
worktree reftable stacks correctly. But we use `strmap_for_each_entry()`
to iterate through the stacks, but the map is in fact not even properly
populated. So instead of checking stacks N^2 times, we actually only end
up checking the reftable stack of the main worktree.

Fix this bug by only verifying the stack of the passed-in worktree and
constructing the backends via `backend_for_worktree()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
78384e2467 refs/reftable: extract function to retrieve backend for worktree
Pull out the logic to retrieve a backend for a given worktree. This
function will be used in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
ab67f0a436 refs/reftable: adapt includes to become consistent
Adapt the includes to be sorted and to use include paths that are
relative to the "refs/" directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
ae38c3a359 refs/files: introduce function to perform normal ref checks
In a subsequent commit we'll introduce new generic checks for direct
refs. These checks will be independent of the actual backend.

Introduce a new function `refs_fsck_ref()` that will be used for this
purpose. At the current point in time it's still empty, but it will get
populated in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:41 -08:00
Patrick Steinhardt
dcecffb616 refs/files: extract generic symref target checks
The consistency checks for the "files" backend contain a couple of
verifications for symrefs that verify generic properties of the target
reference. These properties need to hold for every backend, no matter
whether it's using the "files" or "reftable" backend.

Reimplementing these checks for every single backend doesn't really make
sense. Extract it into a generic `refs_fsck_symref()` function that can
be used by other backends, as well. The "reftable" backend will be wired
up in a subsequent commit.

While at it, improve the consistency checks so that we don't complain
about refs pointing to a non-ref target in case the target refname
format does not verify. Otherwise it's very likely that we'll generate
both error messages, which feels somewhat redundant in this case.

Note that the function has a couple of `UNUSED` parameters. These will
become referenced in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
70b338d60c fsck: drop unused fields from struct fsck_ref_report
The `struct fsck_ref_report` has a couple fields that are intended to
improve the error reporting for broken ref reports by showing which
object ID or target reference the ref points to. These fields are never
set though and are thus essentially unused.

Remove them.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
7b8c36a2a7 refs/files: perform consistency checks for root refs
While the "files" backend already knows to perform consistency checks
for the "refs/" hierarchy, it doesn't verify any of its root refs. Plug
this omission.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
9ebccf744a refs/files: improve error handling when verifying symrefs
The error handling when verifying symbolic refs is a bit on the wild
side:

  - `fsck_report_ref()` can be told to ignore specific errors. If an
    error has been ignored and a previous check raised an unignored
    error, then assigning `ret = fsck_report_ref()` will cause us to
    swallow the previous error.

  - When the target reference is not valid we bail out early without
    checking for other errors.

Fix both of these issues by consistently or'ing the return value and not
bailing out early.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
0ff9cf40b2 refs/files: extract function to check single ref
When checking the consistency of references we create a directory
iterator and then verify each single reference in a loop. The logic to
perform the actual checks is embedded into that loop, which makes it
hard to reuse. But In a subsequent commit we're about to introduce a
second path that wants to verify references.

Prepare for this by extracting the logic to check a single reference
into a standalone function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
2fe33ae20f refs/files: remove useless indirection
The function `files_fsck_refs()` only has a single callsite and forwards
all of its arguments as-is, so it's basically a useless indirection.
Inline the function call.

While at it, also remove the bitwise or that we have for return values.
We don't really want to or them at all, but rather just want to return
an error in case either of the functions has failed.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
5a74903e62 refs/files: remove refs_check_dir parameter
The parameter `refs_check_dir` determines which directory we want to
check references for. But as we always want to check the complete
refs hierarchy, this parameter is always set to "refs".

Drop the parameter and hardcode it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
e615643d2e refs/files: move fsck functions into global scope
When performing consistency checks we pass the functions that perform
the verification down the calling stack. This is somewhat unnecessary
though, as the set of functions doesn't ever change.

Simplify the code by moving the array into global scope and remove the
parameter.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Patrick Steinhardt
df971a7c42 refs/files: simplify iterating through root refs
When iterating through root refs we first need to determine the
directory in which the refs live. This is done by retrieving the root of
the loose refs via `refs->loose->root->name`, and putting it through
`files_ref_path()` to derive the final path.

This is somewhat redundant though: the root name of the loose files
cache is always going to be the empty string. As such, we always end up
passing that empty string to `files_ref_path()` as the ref hierarchy we
want to start. And this actually makes sense: `files_ref_path()` already
computes the location of the root directory, so of course we need to
pass the empty string for the ref hierarchy itself. So going via the
loose ref cache to figure out that the root of a ref hierarchy is empty
is only causing confusion.

But next to the added confusion, it can also lead to a segfault. The
loose ref cache is populated lazily, so it may not always be set. It
seems to be sheer luck that this is a condition we do not currently hit.
The right thing to do would be to call `get_loose_ref_cache()`, which
knows to populate the cache if required.

Simplify the code and fix the potential segfault by simply removing the
indirection via the loose ref cache completely.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:55:40 -08:00
Junio C Hamano
054afa95bc Sync with 'master' 2026-01-12 05:30:02 -08:00
Junio C Hamano
44b4f99803 Merge branch 'je/doc-reset' into next
Documentation updates.

* je/doc-reset:
  doc: git-reset: clarify `git reset <pathspec>`
  doc: git-reset: clarify `git reset [mode]`
  doc: git-reset: clarify intro
  doc: git-reset: reorder the forms
2026-01-12 05:29:51 -08:00
Junio C Hamano
d5dff1bba4 Merge branch 'en/fsck-snapshot-ref-state' into next
"git fsck" used inconsistent set of refs to show a confused
warning, which has been corrected.

* en/fsck-snapshot-ref-state:
  fsck: snapshot default refs before object walk
2026-01-12 05:29:51 -08:00
Junio C Hamano
8745eae506 The 17th batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 05:19:53 -08:00
Junio C Hamano
5323fafdf4 Merge branch 'js/mailmap-karsten-blees'
Mailmap update for Karsten

* js/mailmap-karsten-blees:
  .mailmap: replace Karsten Blees' default address
2026-01-12 05:19:52 -08:00
Junio C Hamano
6506be0304 Merge branch 'ps/t1300-2021-use-test-path-is-helpers'
Test updates.

* ps/t1300-2021-use-test-path-is-helpers:
  t1300: use test helpers instead of `test` command
2026-01-12 05:19:52 -08:00
Junio C Hamano
3235ef374e Merge branch 'rs/commit-stack'
Code clean-up, unifying various hand-rolled "list of commit
objects" and use the commit_stack API.

* rs/commit-stack:
  commit-reach: use commit_stack
  commit-graph: use commit_stack
  commit: add commit_stack_grow()
  shallow: use commit_stack
  pack-bitmap-write: use commit_stack
  commit: add commit_stack_init()
  test-reach: use commit_stack
  remote: use commit_stack for src_commits
  remote: use commit_stack for sent_tips
  remote: use commit_stack for local_commits
  name-rev: use commit_stack
  midx: use commit_stack
  log: use commit_stack
  revision: export commit_stack
2026-01-12 05:19:52 -08:00
Junio C Hamano
0320bcd743 Merge branch 'sb/bundle-uri-without-uri'
Diagnose invalid bundle-URI that lack the URI entry, instead of
crashing.

* sb/bundle-uri-without-uri:
  bundle-uri: validate that bundle entries have a uri
2026-01-12 05:19:52 -08:00
Junio C Hamano
6a4b4e7880 Merge branch 'ja/doc-synopsis-style-more'
More doc style updates.

* ja/doc-synopsis-style-more:
  doc: convert git-remote to synopsis style
  doc: convert git stage to use synopsis block
  doc: convert git-status tables to AsciiDoc format
  doc: convert git-status to synopsis style
  doc: fix t0450-txt-doc-vs-help to select only first synopsis block
2026-01-12 05:19:52 -08:00
Pushkar Singh
220f888d7e t1410: use test helpers in reflog rewind test
Replace raw `test -f` and `! test -f` checks in the rewind test with
`test_path_is_file` and `test_path_is_missing`. This provides clearer
failure diagnostics and keeps the test consistent with the rest of
the test suite.

Signed-off-by: Pushkar Singh <pushkarkumarsingh1970@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-11 20:55:05 -08:00
KJ Tsanaktsidis
a8227ae8d5 http-backend: write newlines to stderr when responding with errors
The not_found and forbidden methods currently do not write a newline to
stderr after the error message. This means that if git-http-backend is
invoked through something like fcgiwrap, and the stderr of that fcgiwrap
process is sent to a logging daemon (e.g. journald), the error messages
of several git-http-backend invocations will just get strung together,
e.g.

> Not a git repository: '/var/lib/git/foo.git'Not a git repository: '/var/lib/git/foo.git'Not a git repository: '/var/lib/git/foo.git'

I think it's git-http-backend's responsibility to format these messages
properly, rather than it being fcgiwrap's job to notice that the script
didn't terminate stderr with a newline and do so itself.

Signed-off-by: KJ Tsanaktsidis <kj@kjtsanaktsidis.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-11 20:54:01 -08:00
Junio C Hamano
1f87b77810 Merge branch 'ml/doc-blame-markup' into next
Doc mark-up update.

* ml/doc-blame-markup:
  doc: git-blame: convert to new doc format
  doc: blame-options: convert to new doc format
2026-01-10 21:54:18 -08:00
Junio C Hamano
236f60e30d Merge branch 'ar/run-command-hook' into next
Fix-up a topic that has recently graduated to 'master'.

* ar/run-command-hook:
  hook: check for NULL pointer before deref
2026-01-10 21:54:18 -08:00
Junio C Hamano
27a1d947d1 Merge branch 'kh/doc-patch-id' into next
"git patch-id" documentation updates.

* kh/doc-patch-id:
  doc: patch-id: --verbatim locks in --stable
  doc: patch-id: spell out the git-diff-tree(1) form
  doc: patch-id: use definite article for the result
  patch-id: use “patch ID” throughout
  doc: patch-id: capitalize Git version
  doc: patch-id: don’t use semicolon between bullet points
2026-01-10 21:54:17 -08:00
Junio C Hamano
48f26103bc Merge branch 'bc/doc-stash-import-export' into next
Update a FAQ entry on synching two separate repositories using the
"git stash export/import" recently introduced.

* bc/doc-stash-import-export:
  gitfaq: document using stash import/export to sync working tree
2026-01-10 21:54:17 -08:00
Junio C Hamano
c33f8ae0bb Merge branch 'kj/t7101-modernize' into next
Test update.

* kj/t7101-modernize:
  t7101: modernize test path checks
2026-01-10 21:54:17 -08:00
Junio C Hamano
a98a468cf0 Merge branch 'ds/builtin-doc-update' into next
Update in-code comment doc to match the current API.

* ds/builtin-doc-update:
  builtin.h: update documentation
2026-01-10 21:54:17 -08:00
Junio C Hamano
6bccdd0e04 Merge branch 'ac/t1420-use-more-direct-check' into next
Test update.

* ac/t1420-use-more-direct-check:
  t1420: modernize the lost-found test
2026-01-10 21:54:17 -08:00
Junio C Hamano
5e3f0240f7 Merge branch 'jk/cat-file-avoid-bitmap-when-unneeded' into next
Fix for a performance regression in "git cat-file".

* jk/cat-file-avoid-bitmap-when-unneeded:
  cat-file: only use bitmaps when filtering
2026-01-10 21:54:17 -08:00
Junio C Hamano
9a633e87df Merge branch 'jk/t-perf-fixes' into next
Perf-test fixes.

* jk/t-perf-fixes:
  t/perf/run: preserve GIT_PERF_* from environment
  t/perf/perf-lib: fix assignment of TEST_OUTPUT_DIRECTORY
2026-01-10 21:54:16 -08:00
Junio C Hamano
90c69f0044 Merge branch 'js/mailmap-karsten-blees' into next
Mailmap update for Karsten

* js/mailmap-karsten-blees:
  .mailmap: replace Karsten Blees' default address
2026-01-10 21:54:16 -08:00
Johannes Schindelin
e97678c4ef .mailmap: replace Karsten Blees' default address
As per a recent email by Karsten, the @dcon.de address no longer works:
https://lore.kernel.org/git/77e768b2-6693-454f-9e11-fb0acdec703c@gmail.com

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-10 09:32:51 -08:00
Colin Stagner
28a7e27cff contrib/subtree: detect rewritten subtree commits
git subtree split --prefix P

detects splits that are outside of path prefix `P` and prunes
them from history graph processing. This improves the performance
of repeated `split --rejoin` with many different prefixes.

Both before and after 83f9dad7d6 (contrib/subtree: fix split with
squashed subtrees, 2025-09-09), the pruning logic does not detect
**rebased** or **cherry-picked** git-subtree commits. If `split`
encounters any of these commits, the split output may have
incomplete history.

All commits authored by

    git subtree merge [--squash] --prefix Q

have a first or second parent that has *only* subtree commits
as ancestors. When splitting a completely different path `P/`,
it is safe to ignore:

1. the merged tree
2. the subtree parent
3. *all* of that parent's ancestry, which applies only to
   path `Q/` and not `P/`.

But this relationship no longer holds if the git-subtree commit
is rebased or otherwise reauthored. After a rebase, the former
git-subtree commit will have other unrelated commits as ancestors.
Ignoring these commits may exclude the history of `P/`,
leading to incomplete `subtree split` output.

The pruning logic relies solely on the `git-subtree-*:` trailers
to detect git-subtree commits, which it blindly accepts without
further validation. The split logic also takes its time about
being wrong: `cmd_split()` execs a `git show` for *every* commit
in the split range… twice. This is inefficient in a shell script.

Add a "reality check" to ignore rebased or rewritten commits:

* Rewrites of non-merge commits cannot be detected, so the new
  detector no longer looks for them.

* Merges carry a `git-subtree-mainline:` trailer with the hash of
  the **first parent**. If this hash differs, or if the "merge"
  commit no longer has multiple parents, a rewrite has occurred.

To increase speed, package this logic in a new method,
`find_other_splits()`. Perform the check up-front by iterating
over a single `git log`. Add ignored subtrees to:

1. the `notree` cache, which excludes them from the `split` history

2. a `prune` negative refs list. The negative refs prevent
   recursing into other subtrees. Since there are potentially a
   *lot* of these, cache them on disk and use rev-list's
   `--stdin` mode.

Reported-by: George <george@mail.dietrich.pub>
Signed-off-by: Colin Stagner <ask+git@howdoi.land>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 20:21:43 -08:00
Adrian Ratiu
3d85d33650 hook: check for NULL pointer before deref
Fix a compiler warning (-Werror=analyzer-deref-before-check) due to
dereferencing the options pointer before NULL checking it.

In practice run_hooks_opt() is never called with a NULL opt struct,
so this just fixes the code to not trigger the warning anymore.

The NULL check is kept as-is because some future patches might end up
calling run_hooks_opt with a NULL opt struct, which is clearly a bug.

While at it, also fix the BUG message function name.

Reported-by: correctmost <cmlists@sent.com>
Suggested-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 18:25:22 -08:00
Elijah Newren
f6b262581a fsck: snapshot default refs before object walk
Fsck has a race when operating on live repositories; consider the
following simple script that writes new commits as fsck runs:

    #!/bin/bash
    git fsck &
    PID=$!

    while ps -p $PID >/dev/null; do
        sleep 3
        git commit -q --allow-empty -m "Another commit"
    done

Since fsck walks objects for connectivity and then reads the refs at the
end to check, this can cause fsck to get confused and think that the new
refs refer to missing commits and that new reflog entries are invalid.
Running the above script in a clone of git.git results in the following
(output ellipsized to remove additional errors of the same type):

    $ ./fsck-while-writing.sh
    Checking ref database: 100% (1/1), done.
    Checking object directories: 100% (256/256), done.
    warning in tag d6602ec5194c87b0fc87103ca4d67251c76f233a: missingTaggerEntry: invalid format - expected 'tagger' line
    Checking objects: 100% (835091/835091), done.
    error: HEAD: invalid reflog entry 2aac9f9286e2164fbf8e4f1d1df53044ace2b310
    error: HEAD: invalid reflog entry 2aac9f9286e2164fbf8e4f1d1df53044ace2b310
    error: HEAD: invalid reflog entry da0f5b80d61844a6f0ad2ddfd57e4fdfa246ea68
    error: HEAD: invalid reflog entry da0f5b80d61844a6f0ad2ddfd57e4fdfa246ea68
    [...]
    error: HEAD: invalid reflog entry 87c8a5c2f6b79d9afa9e941590b9a097b6f7ac09
    error: HEAD: invalid reflog entry d80887a48865e6ad165274b152cbbbed29f8a55a
    error: HEAD: invalid reflog entry d80887a48865e6ad165274b152cbbbed29f8a55a
    error: HEAD: invalid reflog entry 6724f2dfede88bfa9445a333e06e78536c0c6c0d
    error: refs/heads/mybranch invalid reflog entry 2aac9f9286e2164fbf8e4f1d1df53044ace2b310
    error: refs/heads/mybranch: invalid reflog entry 2aac9f9286e2164fbf8e4f1d1df53044ace2b310
    error: refs/heads/mybranch: invalid reflog entry da0f5b80d61844a6f0ad2ddfd57e4fdfa246ea68
    error: refs/heads/mybranch: invalid reflog entry da0f5b80d61844a6f0ad2ddfd57e4fdfa246ea68
    [...]
    error: refs/heads/mybranch: invalid reflog entry 87c8a5c2f6b79d9afa9e941590b9a097b6f7ac09
    error: refs/heads/mybranch: invalid reflog entry d80887a48865e6ad165274b152cbbbed29f8a55a
    error: refs/heads/mybranch: invalid reflog entry d80887a48865e6ad165274b152cbbbed29f8a55a
    error: refs/heads/mybranch: invalid reflog entry 6724f2dfede88bfa9445a333e06e78536c0c6c0d
    Checking connectivity: 833846, done.
    missing commit 6724f2dfede88bfa9445a333e06e78536c0c6c0d
    Verifying commits in commit graph: 100% (242243/242243), done.

We can minimize the race opportunities by taking a snapshot of refs at
program invocation, doing the connectivity check, and then checking the
snapshotted refs afterward.  This avoids races with regular refs between
fsck and adding objects to the database, though it still leaves a race
between a gc and fsck.  We are less concerned about folks simultaneously
running gc with fsck; though, if it becomes an issue, we could lock fsck
during gc.  We definitely do not want to lock fsck during operations
that may add objects to the object store; that would be problematic for
forges.

Note that refs aren't the only problem, though; reflog entries and index
entries could be problematic as well.  For now we punt on index entries
just leaving a TODO comment, and for reflogs we use a coarse solution of
taking the time at the beginning of the program and ignoring reflog
entries newer than that time.  That may be imperfect if dealing with a
network filesystem, so we leave TODO comment for those that want to
improve that handling as well.

As a high level overview:
  * In addition to fsck_handle_ref(), which now is only a few lines long
    to process a ref, there's also a snapshot_ref() which is called
    early in the program for each ref and takes all the error checking
    logic.
  * The iterating over refs that used to be in get_default_heads() plus
    a loop over the arguments now appears in shapshot_refs().
  * There's a new process_refs() as well that kind of looks like the old
    get_default_heads() though it is streamlined due to the work done by
    snapshot_refs().

This combination of changes modifies the output of running the script
(from the beginning of this commit message) to:

    $ ./fsck-while-writing.sh
    Checking ref database: 100% (1/1), done.
    Checking object directories: 100% (256/256), done.
    warning in tag d6602ec5194c87b0fc87103ca4d67251c76f233a: missingTaggerEntry: invalid format - expected 'tagger' line
    Checking objects: 100% (835091/835091), done.
    Checking connectivity: 833846, done.
    Verifying commits in commit graph: 100% (242243/242243), done.

While worries about live updates while running fsck is likely of most
interest for forge operators, it may also benefit those with
automated jobs (such as git maintenance) or even casual users who want
to do other work in their clone while fsck is running.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 18:21:37 -08:00
Derrick Stolee
2ac93bfcbc builtin.h: update documentation
The documentation for the builtin API was moved from the technical
documentation and into a comment in builtin.h by ec14d4ecb5 (builtin.h: take
over documentation from api-builtin.txt, 2017-08-02). This documentation
wasn't updated as part of the major overhaul to include a repository struct
in 9b1cb5070f (builtin: add a repository parameter for builtin functions,
2024-09-13).

There was a brief update regarding the move from *.txt to *.adoc by
e8015223c7 (builtin.h: *.txt -> *.adoc fixes, 2025-03-03).

I noticed that there was quite a bit missing from the old documentation,
which is still visible on git-scm.com [1].

[1] https://github.com/git/git-scm.com/issues/2124

This change updates the documentation in the following ways:

 1. Updates the cmd_foo() prototype to include a repository.
 2. Adds some newlines to have uniformity in the list of flags.
 3. Adds a description of the NO_PARSEOPT flag.
 4. Describes the tests that perform checks on all builtins, which may trip
    up a contributor working on a new builtin.

I double-checked these instructions against a toy example in my local branch
to be sure that it was complete.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 06:37:02 -08:00