The commit 297c09eabb (refs: allow multiple reflog entries for the same
refname, 2024-12-16) added logic for reflogs to exit early in
`lock_ref_for_update()` after obtaining the required lock. This was
added as a performance optimization as it was assumed that no further
processing was required for reflog only updates. However this was
incorrect since for a symref's reflog entry, the update needs to be
populated with the old_oid value. This is done right after the early
exit.
This caused a bug in Git 2.48 where target references of symrefs being
updated would create a corrupted reflog entry for the symref since the
old_oid is not populated. Undo the skip in logic to fix this issue and
also add a test to ensure that such an issue doesn't arise in the
future.
The early exit was added as a performance optimization for reflog-only
updates, but this accidentally broke symref reflog handling. Remove the
optimization since it wasn't essential to the original changes.
Reported-by: Nika Layzell <nika@xxxxxxxxxxxxxxx>
Co-authored-by: Jeff King <peff@xxxxxxxx>
Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
---
Hello,
This patch is based on top of 'maint' so that it can be easily backported.
Sorry for the inconvenience here. This was a premature optimization which
wasn't needed, and unfortunately this wasn't captured by any test.
Karthik
---
refs/files-backend.c | 3 ---
t/t1400-update-ref.sh | 16 ++++++++++++++++
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 5cfb8b7ca8..29f08dced4 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2615,9 +2615,6 @@ 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) {
/*
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index e2316f1dd4..59493dd73f 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -4,6 +4,8 @@
#
test_description='Test git update-ref and basic ref logging'
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
. ./test-lib.sh
@@ -2068,4 +2070,18 @@ do
done
+test_expect_success 'update-ref should also create reflog for HEAD' '
+ test_when_finished "rm -rf repo" &&
+ git init repo &&
+ (
+ cd repo &&
+ test_commit A &&
+ test_commit B &&
+ git rev-parse HEAD >>expect &&
+ git update-ref --create-reflog refs/heads/main HEAD~ &&
+ git rev-parse HEAD@{1} >actual &&
+ test_cmp expect actual
+ )
+'
+
test_done
--
2.47.0
