t1400-update-ref: Add test verifying bug with symrefs in delete_ref()

When deleting a ref through a symref (e.g. using 'git update-ref -d HEAD'
to delete refs/heads/master), we currently fail to remove the packed
version of that ref. This testcase demonstrates the bug.

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

t/t1400-update-ref.sh

@@ -74,6 +74,24 @@ test_expect_success "delete $m (by HEAD)" '
 '
 rm -f .git/$m
 
+test_expect_success \
+	"create $m (by HEAD)" \
+	"git update-ref HEAD $A &&
+	 test $A"' = $(cat .git/'"$m"')'
+test_expect_success \
+	"pack refs" \
+	"git pack-refs --all"
+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" '
+	git update-ref -d HEAD $B &&
+	! grep "$m" .git/packed-refs &&
+	! test -f .git/$m
+'
+rm -f .git/$m
+
 cp -f .git/HEAD .git/HEAD.orig
 test_expect_success "delete symref without dereference" '
 	git update-ref --no-deref -d HEAD &&