In commit ec0becacc9 (run-command: add stdin callback for
parallelization, 2026-01-28), we taught run_processes_parallel() to
ignore SIGPIPE, since we wouldn't want a write() to a broken pipe of one
of the children to take down the whole process.
But there's a subtle ordering issue. After we ignore SIGPIPE, we call
pp_init(), which installs its own cleanup handler for multiple signals
using sigchain_push_common(), which includes SIGPIPE. So if we receive
SIGPIPE while writing to a child, we'll trigger that handler first, pop
it off the stack, and then re-raise (which is then ignored because of
the SIG_IGN we pushed first).
But what does that handler do? It tries to clean up all of the child
processes, under the assumption that when we re-raise the signal we'll
be exiting the process!
So a hook that exits without reading all of its input will cause us to
get SIGPIPE, which will put us in a signal handler that then tries to
kill() that same child.
This seems to be mostly harmless on Linux. The process has already
exited by this point, and though kill() does not complain (since the
process has not been reaped with a wait() call), it does not affect the
exit status of the process.
However, this seems not to be true on all platforms. This case is
triggered by t5401.13, "pre-receive hook that forgets to read its
input". This test fails on NonStop since that hook was converted to the
run_processes_parallel() API.
We can fix it by reordering the code a bit. We should run pp_init()
first, and then push our SIG_IGN onto the stack afterwards, so that it
is truly ignored while feeding the sub-processes.
Note that we also reorder the popping at the end of the function, too.
This is not technically necessary, as we are doing two pops either way,
but now the pops will correctly match their pushes.
This also fixes a related case that we can't test yet. If we did have
more than one process to run, then one child causing SIGPIPE would cause
us to kill() all of the children (which might still actually be
running). But the hook API is the only user of the new feed_pipe
feature, and it does not yet support parallel hook execution. So for now
we'll always execute the processes sequentially. Once parallel hook
execution exists, we'll be able to add a test which covers this.
Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
During Git 2.52 timeframe, we broke streaming computation of object
hash outside a repository, which has been corrected.
* jt/index-fd-wo-repo-regression-fix:
During Git 2.52 timeframe, we broke streaming computation of object
hash outside a repository, which has been corrected.
* jt/index-fd-wo-repo-regression-fix-maint:
object-file: avoid ODB transaction when not writing objects
The experimental `git replay` command learned the `--ref=<ref>` option
to allow specifying which ref to update, overriding the default behavior.
* tc/replay-ref:
replay: allow to specify a ref with option --ref
replay: use stuck form in documentation and help message
builtin/replay: mark options as not negatable
add_files_to_cache() used diff_files() to detect only the paths that
are different between the index and the working tree and add them,
which does not need rename detection, which interfered with unnecessary
conflicts.
* ng/add-files-to-cache-wo-rename:
read-cache: disable renames in add_files_to_cache
Update reftable library part with what is used in libgit2 to improve
portability to different target codebases and platforms.
* ps/reftable-portability:
reftable/system: add abstraction to mmap files
reftable/system: add abstraction to retrieve time in milliseconds
reftable/fsck: use REFTABLE_UNUSED instead of UNUSED
reftable/stack: provide fsync(3p) via system header
reftable: introduce "reftable-system.h" header
Various code clean-up around odb subsystem.
* ps/odb-cleanup:
odb: drop unneeded headers and forward decls
odb: rename `odb_has_object()` flags
odb: use enum for `odb_write_object` flags
odb: rename `odb_write_object()` flags
treewide: use enum for `odb_for_each_object()` flags
CodingGuidelines: document our style for flags
Add the missing &&'s so we properly propagate failures
between commands in the hook helper functions.
Also add a missing mkdir -p arg (found by adding the &&).
Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our description of the reftable format is that it is experimental and
subject to change, but that is no longer true. Remove this statement so
as not to mislead users.
In addition, the documentation says that the files format is the
default, but that is not true if breaking changes mode is on. Correct
this information with a conditional.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In ce1661f9da (odb: add transaction interface, 2025-09-16), existing
ODB transaction logic is adapted to create a transaction interface
at the ODB layer. The intent here is for the ODB transaction
interface to eventually provide an object source agnostic means to
manage transactions.
An unintended consequence of this change though is that
`object-file.c:index_fd()` may enter the ODB transaction path even
when no object write is requested. In non-repository contexts, this
can result in a NULL dereference and segfault. One such case occurs
when running git-diff(1) outside of a repository with
"core.bigFileThreshold" forcing the streaming path in `index_fd()`:
$ echo foo >foo
$ echo bar >bar
$ git -c core.bigFileThreshold=1 diff -- foo bar
In this scenario, the caller only needs to compute the object ID. Object
hashing does not require an ODB, so starting a transaction is both
unnecessary and invalid.
Fix the bug by avoiding the use of ODB transactions in `index_fd()` when
callers are only interested in computing the object hash.
Reported-by: Luca Stefani <luca.stefani.ge1@gmail.com>
Signed-off-by: Justin Tobler <jltobler@gmail.com>
[jc: adjusted to fd13909e (Merge branch 'jt/odb-transaction', 2025-10-02)]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git backfill" is capable of auto-detecting a sparsely checked out
working tree, which was broken.
* th/backfill-auto-detect-sparseness-fix:
backfill: auto-detect sparse-checkout from config
The check in "receive-pack" to prevent a checked out branch from
getting updated via updateInstead mechanism has been corrected.
* ps/receive-pack-updateinstead-in-worktree:
receive-pack: use worktree HEAD for updateInstead
t5516: clean up cloned and new-wt in denyCurrentBranch and worktrees test
t5516: test updateInstead with worktree and unborn bare HEAD
Handling of signed commits and tags in fast-import has been made more
configurable.
* jt/fast-import-signed-modes:
fast-import: add 'abort-if-invalid' mode to '--signed-tags=<mode>'
fast-import: add 'sign-if-invalid' mode to '--signed-tags=<mode>'
fast-import: add 'strip-if-invalid' mode to '--signed-tags=<mode>'
fast-import: add 'abort-if-invalid' mode to '--signed-commits=<mode>'
fast-export: check for unsupported signing modes earlier
The way the "git log -L<range>:<file>" feature is bolted onto the
log/diff machinery is being reworked a bit to make the feature
compatible with more diff options, like -S/G.
* mm/line-log-use-standard-diff-output:
doc: note that -L supports patch formatting and pickaxe options
t4211: add tests for -L with standard diff options
line-log: route -L output through the standard diff pipeline
line-log: fix crash when combined with pickaxe options
Reduce dependency on `the_repository` in add-patch.c file.
* sp/add-patch-with-fewer-the-repository:
add-patch: use repository instance from add_i_state instead of the_repository
Internals of "git fsck" have been refactored to not depend on the
global `the_repository` variable.
* ps/fsck-wo-the-repository:
builtin/fsck: stop using `the_repository` in error reporting
builtin/fsck: stop using `the_repository` when marking objects
builtin/fsck: stop using `the_repository` when checking packed objects
builtin/fsck: stop using `the_repository` with loose objects
builtin/fsck: stop using `the_repository` when checking reflogs
builtin/fsck: stop using `the_repository` when checking refs
builtin/fsck: stop using `the_repository` when snapshotting refs
builtin/fsck: fix trivial dependence on `the_repository`
fsck: drop USE_THE_REPOSITORY
fsck: store repository in fsck options
fsck: initialize fsck options via a function
fetch-pack: move fsck options into function scope
The value of a wrong pointer variable was referenced in an error
message that reported that it shouldn't be NULL.
* yc/path-walk-fix-error-reporting:
path-walk: fix NULL pointer dereference in error message
Fix a regression in writing the commit-graph where commits with dates
exceeding 34 bits (beyond year 2514) could cause an underflow and
crash Git during the generation data overflow chunk writing.
* ps/commit-graph-overflow-fix:
commit-graph: fix writing generations with dates exceeding 34 bits
A handful of inappropriate uses of the_repository have been
rewritten to use the right repository structure instance in the
read-cache.c codepath.
* jd/read-cache-trace-wo-the-repository:
read-cache: use istate->repo for trace2 logging
"git rev-list --maximal-only" has been optimized by borrowing the
logic used by "git show-branch --independent", which computes the
same kind of information much more efficiently.
* ds/rev-list-maximal-only-optim:
rev-list: use reduce_heads() for --maximal-only
p6011: add perf test for rev-list --maximal-only
t6600: test --maximal-only and --independent
"git config list" is the official way to spell "git config -l" and
"git config --list". Use it to update the documentation.
* kh/doc-config-list:
doc: gitcvs-migration: rephrase “man page”
doc: replace git config --list/-l with `list`
"git backfill" is capable of auto-detecting a sparsely checked out
working tree, which was broken.
* th/backfill-auto-detect-sparseness-fix:
backfill: auto-detect sparse-checkout from config
Further work to adjust the codebase for C23 that changes functions
like strchr() that discarded constness when they return a pointer into
a const string to preserve constness.
* jk/c23-const-preserving-fixes-more:
git-compat-util: fix CONST_OUTPARAM typo and indentation
Adjust the codebase for C23 that changes functions like strchr()
that discarded constness when they return a pointer into a const
string to preserve constness.
* jk/c23-const-preserving-fixes:
config: store allocated string in non-const pointer
rev-parse: avoid writing to const string for parent marks
revision: avoid writing to const string for parent marks
rev-parse: simplify dotdot parsing
revision: make handle_dotdot() interface less confusing
A few code paths that spawned child processes for network
connection weren't wait(2)ing for their children and letting "init"
reap them instead; they have been tightened.
* aa/reap-transport-child-processes:
transport-helper, connect: use clean_on_exit to reap children on abnormal exit
pack-objects's --stdin-packs=follow mode learns to handle
excluded-but-open packs.
* tb/stdin-packs-excluded-but-open:
repack: mark non-MIDX packs above the split as excluded-open
pack-objects: support excluded-open packs with --stdin-packs
t7704: demonstrate failure with once-cruft objects above the geometric split
pack-objects: refactor `read_packs_list_from_stdin()` to use `strmap`
pack-objects: plug leak in `read_stdin_packs()`
Object name handling (disambiguation and abbreviation) has been
refactored to be backend-generic, moving logic into the respective
object database backends.
* ps/odb-generic-object-name-handling:
odb: introduce generic `odb_find_abbrev_len()`
object-file: move logic to compute packed abbreviation length
object-name: move logic to compute loose abbreviation length
object-name: simplify computing common prefixes
object-name: abbreviate loose object names without `disambiguate_state`
object-name: merge `update_candidates()` and `match_prefix()`
object-name: backend-generic `get_short_oid()`
object-name: backend-generic `repo_collect_ambiguous()`
object-name: extract function to parse object ID prefixes
object-name: move logic to iterate through packed prefixed objects
object-name: move logic to iterate through loose prefixed objects
odb: introduce `struct odb_for_each_object_options`
oidtree: extend iteration to allow for arbitrary return codes
oidtree: modernize the code a bit
object-file: fix sparse 'plain integer as NULL pointer' error
The 'git rev-list --maximal-only' option filters the output to only
independent commits. A commit is independent if it is not reachable from
other listed commits. Currently this is implemented by doing a full
revision walk and marking parents with CHILD_VISITED to skip non-maximal
commits.
The 'git merge-base --independent' command computes the same result
using reduce_heads(), which uses the more efficient remove_redundant()
algorithm. This is significantly faster because it avoids walking the
entire commit graph.
Add a fast path in rev-list that detects when --maximal-only is the only
interesting option and all input commits are positive (no revision
ranges). In this case, use reduce_heads() directly instead of doing a
full revision walk.
In order to preserve the rest of the output filtering, this computation
is done opportunistically in a new prepare_maximal_independent() method
when possible. If successful, it populates revs->commits with the list
of independent commits and set revs->no_walk to prevent any other walk
from occurring. This allows us to have any custom output be handled
using the existing output code hidden inside
traverse_commit_list_filtered(). A new test is added to demonstrate that
this output is preserved.
The fast path is only used when no other flags complicate the walk or
output format: no UNINTERESTING commits, no limiting options (max-count,
age filters, path filters, grep filters), no output formatting beyond
plain OIDs, and no object listing flags.
Running the p6011 performance test for my copy of git.git, I see the
following improvement with this change:
Test HEAD~1 HEAD
------------------------------------------------------------
6011.2: merge-base --independent 0.03 0.03 +0.0%
6011.3: rev-list --maximal-only 0.06 0.03 -50.0%
6011.4: rev-list --maximal-only --since 0.06 0.06 +0.0%
And for a fresh clone of the Linux kernel repository, I see:
Test HEAD~1 HEAD
------------------------------------------------------------
6011.2: merge-base --independent 0.00 0.00 =
6011.3: rev-list --maximal-only 0.70 0.00 -100.0%
6011.4: rev-list --maximal-only --since 0.70 0.70 +0.0%
In both cases, the performance is indeed matching the behavior of 'git
merge-base --independent', as expected.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a performance test that compares 'git rev-list --maximal-only'
against 'git merge-base --independent'. These two commands are asking
essentially the same thing, but the rev-list implementation is more
generic and hence slower. These performance tests will demonstrate that
in the current state and also be used to show the equivalence in the
future.
We also add a case with '--since' to force the generic walk logic for
rev-list even when we make that future change to use the merge-base
algorithm on a simple walk.
When run on my copy of git.git, I see these results:
Test HEAD
----------------------------------------------
6011.2: merge-base --independent 0.03
6011.3: rev-list --maximal-only 0.06
6011.4: rev-list --maximal-only --since 0.06
These numbers are low, but the --independent calculation is interesting
due to having a lot of local branches that are actually independent.
Running the same test on a fresh clone of the Linux kernel repository
shows a larger difference between the algorithms, especially because the
--independent algorithm is extremely fast when there are no independent
references selected:
Test HEAD
----------------------------------------------
6011.2: merge-base --independent 0.00
6011.3: rev-list --maximal-only 0.70
6011.4: rev-list --maximal-only --since 0.70
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano