<feed xmlns='http://www.w3.org/2005/Atom'>
<title>git/builtin/commit.c, branch v2.37.2</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/git/git.git/
</subtitle>
<id>https://git.shady.money/git/atom?h=v2.37.2</id>
<link rel='self' href='https://git.shady.money/git/atom?h=v2.37.2'/>
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<updated>2022-06-07T21:10:56Z</updated>
<entry>
<title>Merge branch 'ab/plug-leak-in-revisions'</title>
<updated>2022-06-07T21:10:56Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-06-07T21:10:56Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=2da81d1efb0166e1cec7a8582b837994dde6225b'/>
<id>urn:sha1:2da81d1efb0166e1cec7a8582b837994dde6225b</id>
<content type='text'>
Plug the memory leaks from the trickiest API of all, the revision
walker.

* ab/plug-leak-in-revisions: (27 commits)
  revisions API: add a TODO for diff_free(&amp;revs-&gt;diffopt)
  revisions API: have release_revisions() release "topo_walk_info"
  revisions API: have release_revisions() release "date_mode"
  revisions API: call diff_free(&amp;revs-&gt;pruning) in revisions_release()
  revisions API: release "reflog_info" in release revisions()
  revisions API: clear "boundary_commits" in release_revisions()
  revisions API: have release_revisions() release "prune_data"
  revisions API: have release_revisions() release "grep_filter"
  revisions API: have release_revisions() release "filter"
  revisions API: have release_revisions() release "cmdline"
  revisions API: have release_revisions() release "mailmap"
  revisions API: have release_revisions() release "commits"
  revisions API users: use release_revisions() for "prune_data" users
  revisions API users: use release_revisions() with UNLEAK()
  revisions API users: use release_revisions() in builtin/log.c
  revisions API users: use release_revisions() in http-push.c
  revisions API users: add "goto cleanup" for release_revisions()
  stash: always have the owner of "stash_info" free it
  revisions API users: use release_revisions() needing REV_INFO_INIT
  revision.[ch]: document and move code declared around "init"
  ...
</content>
</entry>
<entry>
<title>Merge branch 'ab/commit-plug-leaks'</title>
<updated>2022-05-23T21:39:54Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-05-23T21:39:54Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=ea78f9ee7a595d9e85195c0802d9170fe4ce442e'/>
<id>urn:sha1:ea78f9ee7a595d9e85195c0802d9170fe4ce442e</id>
<content type='text'>
Leakfix in the top-level called-once function.

* ab/commit-plug-leaks:
  commit: fix "author_ident" leak
</content>
</entry>
<entry>
<title>Merge branch 'ep/maint-equals-null-cocci'</title>
<updated>2022-05-20T22:26:59Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-05-20T22:26:59Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=538dc459a0331c48b893c9f6ca0be5917860bb99'/>
<id>urn:sha1:538dc459a0331c48b893c9f6ca0be5917860bb99</id>
<content type='text'>
Introduce and apply coccinelle rule to discourage an explicit
comparison between a pointer and NULL, and applies the clean-up to
the maintenance track.

* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
</content>
</entry>
<entry>
<title>commit: fix "author_ident" leak</title>
<updated>2022-05-12T22:51:32Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-05-12T22:51:07Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=00d8c311050824f841617e954c641ec2ebb300ec'/>
<id>urn:sha1:00d8c311050824f841617e954c641ec2ebb300ec</id>
<content type='text'>
Since 4c28e4ada03 (commit: die before asking to edit the log
message, 2010-12-20), we have been "leaking" the "author_ident" when
prepare_to_commit() fails.  Instead of returning from right there,
introduce an exit status variable and jump to the clean-up label
at the end.

Instead of explicitly releasing the resource with strbuf_release(),
mark the variable with UNLEAK() at the end, together with two other
variables that are already marked as such.  If this were in a
utility function that is called number of times, but these are
different, we should explicitly release resources that grow
proportionally to the size of the problem being solved, but
cmd_commit() is like main() and there is no point in spending extra
cycles to release individual pieces of resource at the end, just
before process exit will clean everything for us for free anyway.

This fixes a leak demonstrated by e.g. "t3505-cherry-pick-empty.sh",
but unfortunately we cannot mark it or other affected tests as passing
now with "TEST_PASSES_SANITIZE_LEAK=true" as we'll need to fix many
other memory leaks before doing so.

Incidentally there are two tests that always passes the leak checker
with or without this change.  Mark them as such.

This is based on an earlier patch by Ævar, but takes a different
approach that is more maintainable.

Signed-off-by: Ævar Arnfjörð Bjarmason &lt;avarab@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'ep/maint-equals-null-cocci' for maint-2.35</title>
<updated>2022-05-02T17:06:04Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-05-02T17:06:00Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=2b0a58d164b0642be3eeb476fecd28114445cdd5'/>
<id>urn:sha1:2b0a58d164b0642be3eeb476fecd28114445cdd5</id>
<content type='text'>
* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
</content>
</entry>
<entry>
<title>tree-wide: apply equals-null.cocci</title>
<updated>2022-05-02T16:50:37Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-05-02T16:50:37Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=afe8a9070bc62db9cfde1e30147178c40d391d93'/>
<id>urn:sha1:afe8a9070bc62db9cfde1e30147178c40d391d93</id>
<content type='text'>
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>revisions API: have release_revisions() release "mailmap"</title>
<updated>2022-04-14T06:56:09Z</updated>
<author>
<name>Ævar Arnfjörð Bjarmason</name>
<email>avarab@gmail.com</email>
</author>
<published>2022-04-13T20:01:46Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=a52f07afcb02b2e09702d54118527fbb9d640895'/>
<id>urn:sha1:a52f07afcb02b2e09702d54118527fbb9d640895</id>
<content type='text'>
Extend the the release_revisions() function so that it frees the
"mailmap" in the "struct rev_info".

The log family of functions now calls the clear_mailmap() function
added in fa8afd18e5a (revisions API: provide and use a
release_revisions(), 2021-09-19), allowing us to whitelist some tests
with "TEST_PASSES_SANITIZE_LEAK=true".

Unfortunately having a pointer to a mailmap in "struct rev_info"
instead of an embedded member that we "own" get a bit messy, as can be
seen in the change to builtin/commit.c.

When we free() this data we won't be able to tell apart a pointer to a
"mailmap" on the heap from one on the stack. As seen in
ea57bc0d41b (log: add --use-mailmap option, 2013-01-05) the "log"
family allocates it on the heap, but in the find_author_by_nickname()
code added in ea16794e430 (commit: search author pattern against
mailmap, 2013-08-23) we allocated it on the stack instead.

Ideally we'd simply change that member to a "struct string_list
mailmap" and never free() the "mailmap" itself, but that would be a
much larger change to the revisions API.

We have code that needs to hand an existing "mailmap" to a "struct
rev_info", while we could change all of that, let's not go there
now.

The complexity isn't in the ownership of the "mailmap" per-se, but
that various things assume a "rev_info.mailmap == NULL" means "doesn't
want mailmap", if we changed that to an init'd "struct string_list
we'd need to carefully refactor things to change those assumptions.

Let's instead always free() it, and simply declare that if you add
such a "mailmap" it must be allocated on the heap. Any modern libc
will correctly panic if we free() a stack variable, so this should be
safe going forward.

Signed-off-by: Ævar Arnfjörð Bjarmason &lt;avarab@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>revisions API users: add straightforward release_revisions()</title>
<updated>2022-04-14T06:56:08Z</updated>
<author>
<name>Ævar Arnfjörð Bjarmason</name>
<email>avarab@gmail.com</email>
</author>
<published>2022-04-13T20:01:36Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=2108fe4a1976f95821e13503fd331f075da398c6'/>
<id>urn:sha1:2108fe4a1976f95821e13503fd331f075da398c6</id>
<content type='text'>
Add a release_revisions() to various users of "struct rev_list" in
those straightforward cases where we only need to add the
release_revisions() call to the end of a block, and don't need to
e.g. refactor anything to use a "goto cleanup" pattern.

Signed-off-by: Ævar Arnfjörð Bjarmason &lt;avarab@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>hooks: fix an obscure TOCTOU "did we just run a hook?" race</title>
<updated>2022-03-07T21:00:53Z</updated>
<author>
<name>Ævar Arnfjörð Bjarmason</name>
<email>avarab@gmail.com</email>
</author>
<published>2022-03-07T12:33:46Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=a8cc594333848713b8e772cccf8159196ea85ede'/>
<id>urn:sha1:a8cc594333848713b8e772cccf8159196ea85ede</id>
<content type='text'>
Fix a Time-of-check to time-of-use (TOCTOU) race in code added in
680ee550d72 (commit: skip discarding the index if there is no
pre-commit hook, 2017-08-14).

This obscure race condition can occur if we e.g. ran the "pre-commit"
hook and it modified the index, but hook_exists() returns false later
on (e.g., because the hook itself went away, the directory became
unreadable, etc.). Then we won't call discard_cache() when we should
have.

The race condition itself probably doesn't matter, and users would
have been unlikely to run into it in practice. This problem has been
noted on-list when 680ee550d72 was discussed[1], but had not been
fixed.

This change is mainly intended to improve the readability of the code
involved, and to make reasoning about it more straightforward. It
wasn't as obvious what we were trying to do here, but by having an
"invoked_hook" it's clearer that e.g. our discard_cache() is happening
because of the earlier hook execution.

Let's also change this for the push-to-checkout hook. Now instead of
checking if the hook exists and either doing a push to checkout or a
push to deploy we'll always attempt a push to checkout. If the hook
doesn't exist we'll fall back on push to deploy. The same behavior as
before, without the TOCTOU race. See 0855331941b (receive-pack:
support push-to-checkout hook, 2014-12-01) for the introduction of the
previous behavior.

This leaves uses of hook_exists() in two places that matter. The
"reference-transaction" check in refs.c, see 67541597670 (refs:
implement reference transaction hook, 2020-06-19), and the
"prepare-commit-msg" hook, see 66618a50f9c (sequencer: run
'prepare-commit-msg' hook, 2018-01-24).

In both of those cases we're saving ourselves CPU time by not
preparing data for the hook that we'll then do nothing with if we
don't have the hook. So using this "invoked_hook" pattern doesn't make
sense in those cases.

The "reference-transaction" and "prepare-commit-msg" hook also aren't
racy. In those cases we'll skip the hook runs if we race with a new
hook being added, whereas in the TOCTOU races being fixed here we were
incorrectly skipping the required post-hook logic.

1. https://lore.kernel.org/git/20170810191613.kpmhzg4seyxy3cpq@sigill.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason &lt;avarab@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'ab/date-mode-release'</title>
<updated>2022-02-25T23:47:36Z</updated>
<author>
<name>Junio C Hamano</name>
<email>gitster@pobox.com</email>
</author>
<published>2022-02-25T23:47:36Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/git/commit/?id=0a01df08c03fe707e22795de7bd1d763ed02e9e1'/>
<id>urn:sha1:0a01df08c03fe707e22795de7bd1d763ed02e9e1</id>
<content type='text'>
Plug (some) memory leaks around parse_date_format().

* ab/date-mode-release:
  date API: add and use a date_mode_release()
  date API: add basic API docs
  date API: provide and use a DATE_MODE_INIT
  date API: create a date.h, split from cache.h
  cache.h: remove always unused show_date_human() declaration
</content>
</entry>
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