reflog: don't be noisy on empty reflogs

avar · gitster · commit 57be9c6deeb1 · 2022-03-13T18:37:08.000Z
Fix a regression in my daf1d82 (reflog expire: don't use lookup_commit_reference_gently(), 2021-12-22), in changing from lookup_commit_reference_gently() to lookup_commit() we stopped trying to call deref_tag() and parse_object() on the provided OID, but we also started returning non-NULL for the null_oid(). As a result we'd emit an error() via mark_reachable() later in this function as we tried to invoke parse_commit() on it. Reported-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Tested-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/reflog.c b/builtin/reflog.c
@@ -382,6 +382,8 @@ static void reflog_expiry_prepare(const char *refname,
 		cb->unreachable_expire_kind = UE_HEAD;
 	} else {
 		commit = lookup_commit(the_repository, oid);
+		if (commit && is_null_oid(&commit->object.oid))
+			commit = NULL;
 		cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;
 	}
 
diff --git a/t/t1410-reflog.sh b/t/t1410-reflog.sh
@@ -422,4 +422,13 @@ test_expect_success 'expire with multiple worktrees' '
 	)
 '
 
+test_expect_success REFFILES 'empty reflog' '
+	test_when_finished "rm -rf empty" &&
+	git init empty &&
+	test_commit -C empty A &&
+	>empty/.git/logs/refs/heads/foo &&
+	git -C empty reflog expire --all 2>err &&
+	test_must_be_empty err
+'
+
 test_done

Original file line number	Diff line number	Diff line change
`@@ -382,6 +382,8 @@ static void reflog_expiry_prepare(const char *refname,`
`382`	`382`	`cb->unreachable_expire_kind = UE_HEAD;`
`383`	`383`	`} else {`
`384`	`384`	`commit = lookup_commit(the_repository, oid);`
	`385`	`+ if (commit && is_null_oid(&commit->object.oid))`
	`386`	`+ commit = NULL;`
`385`	`387`	`cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;`
`386`	`388`	`}`
`387`	`389`
Original file line number	Diff line number	Diff line change
`@@ -422,4 +422,13 @@ test_expect_success 'expire with multiple worktrees' '`
`422`	`422`	`)`
`423`	`423`	`'`
`424`	`424`
	`425`	`+test_expect_success REFFILES 'empty reflog' '`
	`426`	`+ test_when_finished "rm -rf empty" &&`
	`427`	`+ git init empty &&`
	`428`	`+ test_commit -C empty A &&`
	`429`	`+ >empty/.git/logs/refs/heads/foo &&`
	`430`	`+ git -C empty reflog expire --all 2>err &&`
	`431`	`+ test_must_be_empty err`
	`432`	`+'`
	`433`	`+`
`425`	`434`	`test_done`