Fix failure to delete a packed ref through a symref

When deleting a ref through a symref (e.g. using 'git update-ref -d HEAD'
to delete refs/heads/master), we would remove the loose ref, but a packed
version of the same ref would remain, the end result being that instead of
deleting refs/heads/master we would appear to reset it to its state as of
the last repack.

This patch fixes the issue, by making sure we pass the correct ref name
when invoking repack_without_ref() from within delete_ref().

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -1778,7 +1778,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 	 * packed one.  Also, if it was not loose we need to repack
 	 * without it.
 	 */
-	ret |= repack_without_ref(refname);
+	ret |= repack_without_ref(lock->ref_name);
 
 	unlink_or_warn(git_path("logs/%s", lock->ref_name));
 	invalidate_ref_cache(NULL);

t/t1400-update-ref.sh

@@ -85,7 +85,7 @@ test_expect_success \
 	"move $m (by HEAD)" \
 	"git update-ref HEAD $B $A &&
 	 test $B"' = $(cat .git/'"$m"')'
-test_expect_failure "delete $m (by HEAD) should remove both packed and loose $m" '
+test_expect_success "delete $m (by HEAD) should remove both packed and loose $m" '
 	git update-ref -d HEAD $B &&
 	! grep "$m" .git/packed-refs &&
 	! test -f .git/$m