t1408: add a test of stale packed refs covered by loose refs

It is OK for the packed-refs file to contain old reference definitions
that might even refer to objects that have since been
garbage-collected, as long as there is a corresponding loose reference
definition that overrides it. Add a test that such references don't
cause problems.

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

diff --git a/t/t1408-packed-refs.sh b/t/t1408-packed-refs.sh
new file mode 100755 (executable)
index 0000000..1e44a17
--- /dev/null
+++ b/t/t1408-packed-refs.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+test_description='packed-refs entries are covered by loose refs'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+       test_tick &&
+       git commit --allow-empty -m one &&
+       one=$(git rev-parse HEAD) &&
+       git for-each-ref >actual &&
+       echo "$one commit       refs/heads/master" >expect &&
+       test_cmp expect actual &&
+
+       git pack-refs --all &&
+       git for-each-ref >actual &&
+       echo "$one commit       refs/heads/master" >expect &&
+       test_cmp expect actual &&
+
+       git checkout --orphan another &&
+       test_tick &&
+       git commit --allow-empty -m two &&
+       two=$(git rev-parse HEAD) &&
+       git checkout -B master &&
+       git branch -D another &&
+
+       git for-each-ref >actual &&
+       echo "$two commit       refs/heads/master" >expect &&
+       test_cmp expect actual &&
+
+       git reflog expire --expire=now --all &&
+       git prune &&
+       git tag -m v1.0 v1.0 master
+'
+
+test_expect_success 'no error from stale entry in packed-refs' '
+       git describe master >actual 2>&1 &&
+       echo "v1.0" >expect &&
+       test_cmp expect actual
+'
+
+test_done