Merge branch 'ma/create-pseudoref-with-null-old-oid'

"git update-ref A B" is supposed to ensure that ref A does not yet
exist when B is a NULL OID, but this check was not done correctly
for pseudo-refs outside refs/ hierarchy, e.g. MERGE_HEAD.

* ma/create-pseudoref-with-null-old-oid:
  refs: handle zero oid for pseudorefs
  t1400: add tests around adding/deleting pseudorefs
  refs.c: refer to "object ID", not "sha1", in error messages

1 files changed, 60 insertions, 0 deletions

diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 664a3a4..faf0dfe 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -457,6 +457,66 @@ test_expect_success 'git cat-file blob master@{2005-05-26 23:42}:F (expect OTHER
 	test OTHER = $(git cat-file blob "master@{2005-05-26 23:42}:F")
 '
 
+# Test adding and deleting pseudorefs
+
+test_expect_success 'given old value for missing pseudoref, do not create' '
+	test_must_fail git update-ref PSEUDOREF $A $B 2>err &&
+	test_path_is_missing .git/PSEUDOREF &&
+	grep "could not read ref" err
+'
+
+test_expect_success 'create pseudoref' '
+	git update-ref PSEUDOREF $A &&
+	test $A = $(cat .git/PSEUDOREF)
+'
+
+test_expect_success 'overwrite pseudoref with no old value given' '
+	git update-ref PSEUDOREF $B &&
+	test $B = $(cat .git/PSEUDOREF)
+'
+
+test_expect_success 'overwrite pseudoref with correct old value' '
+	git update-ref PSEUDOREF $C $B &&
+	test $C = $(cat .git/PSEUDOREF)
+'
+
+test_expect_success 'do not overwrite pseudoref with wrong old value' '
+	test_must_fail git update-ref PSEUDOREF $D $E 2>err &&
+	test $C = $(cat .git/PSEUDOREF) &&
+	grep "unexpected object ID" err
+'
+
+test_expect_success 'delete pseudoref' '
+	git update-ref -d PSEUDOREF &&
+	test_path_is_missing .git/PSEUDOREF
+'
+
+test_expect_success 'do not delete pseudoref with wrong old value' '
+	git update-ref PSEUDOREF $A &&
+	test_must_fail git update-ref -d PSEUDOREF $B 2>err &&
+	test $A = $(cat .git/PSEUDOREF) &&
+	grep "unexpected object ID" err
+'
+
+test_expect_success 'delete pseudoref with correct old value' '
+	git update-ref -d PSEUDOREF $A &&
+	test_path_is_missing .git/PSEUDOREF
+'
+
+test_expect_success 'create pseudoref with old OID zero' '
+	git update-ref PSEUDOREF $A $Z &&
+	test $A = $(cat .git/PSEUDOREF)
+'
+
+test_expect_success 'do not overwrite pseudoref with old OID zero' '
+	test_when_finished git update-ref -d PSEUDOREF &&
+	test_must_fail git update-ref PSEUDOREF $B $Z 2>err &&
+	test $A = $(cat .git/PSEUDOREF) &&
+	grep "already exists" err
+'
+
+# Test --stdin
+
 a=refs/heads/a
 b=refs/heads/b
 c=refs/heads/c