update-ref --no-deref -d: handle the case when the pointed ref is packed

In this case we did nothing in the past, but we should delete the
reference in fact.

The problem was that when the symref is not packed but the referenced
ref is packed, then we assumed that the symref is packed as well, but
symrefs are never packed.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -920,7 +920,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 	lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 	if (!lock)
 		return 1;
-	if (!(flag & REF_ISPACKED)) {
+	if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
 		/* loose */
 		const char *path;
 

t/t1400-update-ref.sh

@@ -82,6 +82,17 @@ test_expect_success "delete symref without dereference" '
 '
 cp -f .git/HEAD.orig .git/HEAD
 
+test_expect_success "delete symref without dereference when the referred ref is packed" '
+	echo foo >foo.c &&
+	git add foo.c &&
+	git commit -m foo &&
+	git pack-refs --all &&
+	git update-ref --no-deref -d HEAD &&
+	! test -f .git/HEAD
+'
+cp -f .git/HEAD.orig .git/HEAD
+git update-ref -d $m
+
 test_expect_success '(not) create HEAD with old sha1' "
 	test_must_fail git update-ref HEAD $A $B
 "