[PATCH v5] pull, fetch: fix segfault in --set-upstream option
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- Dec 7, 2021, 22:04 UTC
- Message-ID
- <patch-v5-1.1-69ab40d623b-20211207T215115Z-avarab@gmail.com>
- In-Reply-To
- <xmqqy24w5eqx.fsf@gitster.g>
Fix a segfault in the --set-upstream option added in 24bc1a12926 (pull, fetch: add --set-upstream option, 2019-08-19) added in v2.24.0.
The code added there did not do the same checking we do for "git branch" itself since 8efb8899cfe (branch: segfault fixes and validation, 2013-02-23), which in turn fixed the same sort of segfault I'm fixing now in "git branch --set-upstream-to", see 6183d826ba6 (branch: introduce --set-upstream-to, 2012-08-20).
The warning message I'm adding here is an amalgamation of the error added for "git branch" in 8efb8899cfe, and the error output install_branch_config() itself emits, i.e. it trims "refs/heads/" from the name and says "branch X on remote", not "branch refs/heads/X on remote".
I think it would make more sense to simply die() here, but in the other checks for --set-upstream added in 24bc1a12926 we issue a warning() instead. Let's do the same here for consistency for now.
There was an earlier submitted alternate way of fixing this in [1], due to that patch breaking threading with the original report at [2] I didn't notice it before authoring this version. I think the more detailed warning message here is better, and we should also have tests for this behavior.
The --no-rebase option to "git pull" is needed as of the recently merged 7d0daf3f12f (Merge branch 'en/pull-conflicting-options', 2021-08-30).
1. https://lore.kernel.org/git/20210706162238.575988-1-clemens@endorphin.org/ 2. https://lore.kernel.org/git/CAG6gW_uHhfNiHGQDgGmb1byMqBA7xa8kuH1mP-wAPEe5Tmi2Ew@mail.gmail.com/
Reported-by: Clemens Fruhwirth <clemens@endorphin.org> Reported-by: Jan Pokorný <poki@fnusa.cz> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> ---
Show 8 quoted lines
> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes: > >> So i'd think that any proposed behavior change there should come >> independent of a narrow segfault fix, let's fix that, and then change >> how "fetch --set-upstream-to" works in general. > > Sound good. I won't have time to go hunting for old patch from the > archive today, though.
In case it help a v5 that's really just a re-send of the v4 at https://lore.kernel.org/git/patch-v4-1.1-0caa9a89a86-20210831T135212Z-avarab@gmail.com/
Range-diff against v4: 1: 0caa9a89a86 = 1: 69ab40d623b pull, fetch: fix segfault in --set-upstream option
builtin/fetch.c | 10 ++++++++++ t/t5553-set-upstream.sh | 22 ++++++++++++++++++++++ 2 files changed, 32 insertions(+)
diff --git a/builtin/fetch.c b/builtin/fetch.c index f7abbc31ff1..7f3d2fdc9ce 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -1638,6 +1638,16 @@ static int do_fetch(struct transport *transport, } } if (source_ref) { + if (!branch) { + const char *shortname = source_ref->name; + skip_prefix(shortname, "refs/heads/", &shortname); + + warning(_("could not set upstream of HEAD to '%s' from '%s' when " + "it does not point to any branch."), + shortname, transport->remote->name); + goto skip; + } + if (!strcmp(source_ref->name, "HEAD") || starts_with(source_ref->name, "refs/heads/")) install_branch_config(0, diff --git a/t/t5553-set-upstream.sh b/t/t5553-set-upstream.sh index 9c12c0f8c32..48050162c27 100755 --- a/t/t5553-set-upstream.sh +++ b/t/t5553-set-upstream.sh @@ -91,6 +91,17 @@ test_expect_success 'fetch --set-upstream with valid URL sets upstream to URL' ' check_config_missing other2 ' +test_expect_success 'fetch --set-upstream with a detached HEAD' ' + git checkout HEAD^0 && + test_when_finished "git checkout -" && + cat >expect <<-\EOF && + warning: could not set upstream of HEAD to '"'"'main'"'"' from '"'"'upstream'"'"' when it does not point to any branch. + EOF + git fetch --set-upstream upstream main 2>actual.raw && + grep ^warning: actual.raw >actual && + test_cmp expect actual +' + # tests for pull --set-upstream test_expect_success 'setup bare parent pull' ' @@ -178,4 +189,15 @@ test_expect_success 'pull --set-upstream with valid URL and branch sets branch' check_config_missing other2 ' +test_expect_success 'pull --set-upstream with a detached HEAD' ' + git checkout HEAD^0 && + test_when_finished "git checkout -" && + cat >expect <<-\EOF && + warning: could not set upstream of HEAD to '"'"'main'"'"' from '"'"'upstream'"'"' when it does not point to any branch. + EOF + git pull --no-rebase --set-upstream upstream main 2>actual.raw && + grep ^warning: actual.raw >actual && + test_cmp expect actual +' + test_done
-- 2.34.1.926.g895e15e0c0c