Re: [PATCH] refs: fix migration of reflogs respecting "core.logAllRefUpdates"

Patrick Steinhardt [off-list ref] writes:

In 246cebe320 (refs: add support for migrating reflogs, 2024-12-16) we
have added support to git-refs(1) to migrate reflogs between reference
backends. It was reported [1] though that not we don't migrate reflogs
for a subset of references, most importantly "refs/stash".

This issue is caused by us still honoring "core.logAllRefUpdates" when
trying to migrate reflogs: we do queue the updates, but depending on the
value of that config we may decide to just skip writing the reflog entry
altogether. And given that:

  - The default for "core.logAllRefUpdates" is to only create reflogs
    for branches, remotes, note refs and "HEAD"

  - "refs/stash" is neither of these ref types.

We end up skipping the reflog creation for that particular reference.

Fix the bug by setting `REF_FORCE_CREATE_REFLOG`, which instructs the
ref backends to create the reflog entry regardless of the config or any
preexisting state.

Thanks for a clear problem analysis description.  The appraoch makes
perfect sense.

Will queue.

+		test_expect_success "$from_format -> $to_format: stash is retained" '
+			test_when_finished "rm -rf repo" &&
+			git init --ref-format=$from_format repo &&
+			(
+				cd repo &&
+				test_commit initial A &&
+				echo foo >A &&
+				git stash push &&
+				echo bar >A &&
+				git stash push &&
+				git stash list >expect.reflog &&
+				test_migration . "$to_format" &&
+				git stash list >actual.reflog &&
+				test_cmp expect.reflog actual.reflog
+			)
+		'
 	done
 done
 

---
base-commit: f93ff170b93a1782659637824b25923245ac9dd1
change-id: 20250122-b4-pks-reflog-migration-fix-stash-d1fe7380f84a