t3211: demonstrate loss of peeled refs if a packed ref is deleted

Add a test that demonstrates that the peeled values recorded in
packed-refs are lost if a packed ref is deleted.  (The code in
repack_without_ref() doesn't even attempt to write peeled refs.)  This
will be fixed in a moment.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3211-peel-ref.sh

@@ -61,4 +61,13 @@ test_expect_success 'refs are peeled outside of refs/tags (old packed)' '
 	test_cmp expect actual
 '
 
+test_expect_failure 'peeled refs survive deletion of packed ref' '
+	git pack-refs --all &&
+	cp .git/packed-refs fully-peeled &&
+	git branch yadda &&
+	git pack-refs --all &&
+	git branch -d yadda &&
+	test_cmp fully-peeled .git/packed-refs
+'
+
 test_done