Add pack-refs and show-ref test cases.

Some of these test cases are from Junio.
One test case is commented out because it doesn't work right now.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

t/t3210-pack-refs.sh

@@ -0,0 +1,70 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Amos Waterland
+# Copyright (c) 2006 Christian Couder
+#
+
+test_description='git pack-refs should not change the branch semantic
+
+This test runs git pack-refs and git show-ref and checks that the branch
+semantic is still the same.
+'
+. ./test-lib.sh
+
+test_expect_success \
+    'prepare a trivial repository' \
+    'echo Hello > A &&
+     git-update-index --add A &&
+     git-commit -m "Initial commit." &&
+     HEAD=$(git-rev-parse --verify HEAD)'
+
+SHA1=
+
+test_expect_success \
+    'see if git show-ref works as expected' \
+    'git-branch a &&
+     SHA1=$(< .git/refs/heads/a) &&
+     echo "$SHA1 refs/heads/a" >expect &&
+     git-show-ref a >result &&
+     diff expect result'
+
+test_expect_success \
+    'see if a branch still exists when packed' \
+    'git-branch b &&
+     git-pack-refs &&
+     rm .git/refs/heads/b &&
+     echo "$SHA1 refs/heads/b" >expect &&
+     git-show-ref b >result &&
+     diff expect result'
+
+# test_expect_failure \
+#     'git branch c/d should barf if branch c exists' \
+#     'git-branch c &&
+#      git-pack-refs &&
+#      rm .git/refs/heads/c &&
+#      git-branch c/d'
+
+test_expect_success \
+    'see if a branch still exists after git pack-refs --prune' \
+    'git-branch e &&
+     git-pack-refs --prune &&
+     echo "$SHA1 refs/heads/e" >expect &&
+     git-show-ref e >result &&
+     diff expect result'
+
+test_expect_failure \
+    'see if git pack-refs --prune remove ref files' \
+    'git-branch f &&
+     git-pack-refs --prune &&
+     ls .git/refs/heads/f'
+
+test_expect_success \
+    'git branch g should work when git branch g/h has been deleted' \
+    'git-branch g/h &&
+     git-pack-refs --prune &&
+     git-branch -d g/h &&
+     git-branch g &&
+     git-pack-refs &&
+     git-branch -d g'
+
+test_done