@leroysheep / LeeRoySheep / commits / 3519492430

refs: fix creation of reflog entries for symrefs

The commit 297c09eabb (refs: allow multiple reflog entries for the same refname, 2024-12-16) added logic to exit early in `lock_ref_for_update()` after obtaining the required lock. This was added as a performance optimization on a false assumption that no further processing was required for reflog-only updates. However the assumption was wrong. For a symref's reflog entry, the update needs to be populated with the old_oid value, but the early exit skipped this necessary step. This caused a bug in Git 2.48 in the files backend where target references of symrefs being updated would create a corrupted reflog entry for the symref since the old_oid is not populated. Everything the early exit skipped in the code path is necessary for both regular and symbolic ref, so eliminate the mistaken optimization, and also add a test to ensure that such an issue doesn't arise in the future. Reported-by: Nika Layzell <nika@thelayzells.com> Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Karthik Nayak committed Jan 23, 2025 at 12:29 UTC 3519492430ba26cadcdb215730a6c8e1bcf5b9cf
2 files changed +9 -3
refs/files-backend.c
-3
index 8953d1c6d3..1c0e24a855 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2611,9 +2611,6 @@ static int lock_ref_for_update(struct files_ref_store *refs, update->backend_data = lock; - if (update->flags & REF_LOG_ONLY) - goto out; - if (update->type & REF_ISSYMREF) { if (update->flags & REF_NO_DEREF) { /*
t/t1400-update-ref.sh
+9
index e2316f1dd4..29045aad43 100755 --- a/t/t1400-update-ref.sh +++ b/t/t1400-update-ref.sh @@ -2068,4 +2068,13 @@ do done +test_expect_success 'update-ref should also create reflog for HEAD' ' + test_commit to-rewind && + git rev-parse HEAD >expect && + head=$(git symbolic-ref HEAD) && + git update-ref --create-reflog "$head" HEAD~ && + git rev-parse HEAD@{1} >actual && + test_cmp expect actual +' + test_done