When gc --auto is called in the presence of worktrees, it fails to take
*all* reflogs into account when trying to retain reachable objects, and as
a consequence data integrity goes pretty much to hell.
This patch provides a test case in the hopes that this bug gets fixed,
after an initial attempt has stalled for eight months already.
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
t/t6500-gc.sh | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index 1762dfa6a3..e24a4fb611 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -67,5 +67,44 @@ test_expect_success 'auto gc with too many loose objects does not attempt to cre
test_line_count = 2 new # There is one new pack and its .idx
'
+trigger_auto_gc () {
+ # This is unfortunately very, very ugly
+ gdir="$(git rev-parse --git-common-dir)" &&
+ mkdir -p "$gdir"/objects/17 &&
+ touch "$gdir"/objects/17/17171717171717171717171717171717171717 &&
+ touch "$gdir"/objects/17/17171717171717171717171717171717171718 &&
+ git -c gc.auto=1 -c gc.pruneexpire=now -c gc.autodetach=0 gc --auto
+}
+
+test_expect_failure 'gc respects refs/reflogs in all worktrees' '
+ test_commit something &&
+ git worktree add worktree &&
+ (
+ cd worktree &&
+ git checkout --detach &&
+ # avoid implicit tagging of test_commit
+ echo 1 >something.t &&
+ test_tick &&
+ git commit -m worktree-reflog something.t &&
+ git rev-parse --verify HEAD >../commit-reflog &&
+ echo 2 >something.t &&
+ test_tick &&
+ git commit -m worktree-ref something.t &&
+ git rev-parse --verify HEAD >../commit-ref
+ ) &&
+ trigger_auto_gc &&
+ git rev-parse --verify $(cat commit-ref)^{commit} &&
+ git rev-parse --verify $(cat commit-reflog)^{commit} &&
+
+ # Now, add a reflog in the top-level dir and verify that `git gc` in
+ # the worktree does not purge that
+ git checkout --detach &&
+ echo 3 >something.t &&
+ test_tick &&
+ git commit -m commondir-reflog something.t &&
+ git rev-parse --verify HEAD >commondir-reflog &&
+ (cd worktree && trigger_auto_gc) &&
+ git rev-parse --verify $(cat commondir-reflog)^{commit}
+'
test_done
--
2.11.1.windows.1