[PATCH 1/6] stash: tell setup_revisions() to free our allocated strings
- From
Jeff King <peff@peff.net>
- Date
- Sep 19, 2025, 22:40 UTC
- Message-ID
- <20250919224027.GA594545@coredump.intra.peff.net>
- In-Reply-To
- <20250919223351.GA3906184@coredump.intra.peff.net>
In "git stash show", we do a first pass of parsing our command line options by splitting them into revision args and stash args. These are stored in strvecs, and we pass the revision args to setup_revisions().
But setup_revisions() may modify the argv we pass it, causing us to leak some of the entries. In particular, if it sees a "--" string, that will be dropped from argv. This is the same as other cases addressed by f92dbdbc6a (revisions API: don't leak memory on argv elements that need free()-ing, 2022-08-02), and we should fix it the same way: by passing the free_removed_argv_elements option to setup_revisions().
I've added a test here which fails when built with SANITIZE=leak because it calls "git stash show --". This by itself is not a very interesting invocation, because there is nothing after the "--", and thus the "--" is not really doing anything.
But I think the current parsing in show_stash() is a little questionable. It splits the arguments into revision options and stash options solely based on the presence of a leading dash, with no regard to "--" at all. So:
git stash show -- foo
will take "foo" as a stash option before we even pass anything to setup_revisions(). And something like:
git stash show -- 1
will show stash@{1}. But I would expect anything after the "--" to be a pathspec. So in this example it would show only the part of the diff that touched "foo". And something like:
git stash show -p 1 -- foo
would treat "1" as a stash and "foo" as a pathspec.
That may be something we want to fix, but I want to focus here on the leak-fixing without changing behavior. So this test is a little odd, but does what we want without locking us in to any particular behavior (we only care that "--" by itself does not change the output nor leak).
Signed-off-by: Jeff King <peff@peff.net> --- I wonder if anybody actually cares that "git stash show -- foo" will treat "foo" as a stash. If not, then it would probably be a fairly easy #leftoverbits project to teach it to stop there and retain everything after as a rev argument (which would then treat it like a pathspec).
builtin/stash.c | 3 ++- t/t3903-stash.sh | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/builtin/stash.c b/builtin/stash.c index f5ddee5c7f..e5ab3c4cf5 100644 --- a/builtin/stash.c +++ b/builtin/stash.c @@ -957,6 +957,7 @@ static void diff_include_untracked(const struct stash_info *info, struct diff_op static int show_stash(int argc, const char **argv, const char *prefix, struct repository *repo UNUSED) { + struct setup_revision_opt opt = { .free_removed_argv_elements = 1 }; int i; int ret = -1; struct stash_info info = STASH_INFO_INIT; @@ -1015,7 +1016,7 @@ static int show_stash(int argc, const char **argv, const char *prefix, } } - argc = setup_revisions(revision_args.nr, revision_args.v, &rev, NULL); + argc = setup_revisions(revision_args.nr, revision_args.v, &rev, &opt); if (argc > 1) goto usage; if (!rev.diffopt.output_format) { diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh index 0bb4648e36..1c9e589bbe 100755 --- a/t/t3903-stash.sh +++ b/t/t3903-stash.sh @@ -1741,4 +1741,10 @@ test_expect_success 'submodules does not affect the branch recorded in stash mes ) ' +test_expect_success 'stash show handles --' ' + git stash show >expect && + git stash show -- >actual && + test_cmp expect actual +' + test_done
-- 2.51.0.568.g6b54b97edf