1 files changed, 35 insertions, 0 deletions
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 08bd8fd8d6..d226930412 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -1102,6 +1102,41 @@ test_expect_success 'stdin -z delete refs works with packed and loose refs' '
 	test_must_fail git rev-parse --verify -q $c
 '
 
+test_expect_success 'fails with duplicate HEAD update' '
+	git branch target1 $A &&
+	git checkout target1 &&
+	cat >stdin <<-EOF &&
+	update refs/heads/target1 $C
+	option no-deref
+	update HEAD $B
+	EOF
+	test_must_fail git update-ref --stdin <stdin 2>err &&
+	grep "fatal: multiple updates for '\''HEAD'\'' (including one via its referent .refs/heads/target1.) are not allowed" err &&
+	echo "refs/heads/target1" >expect &&
+	git symbolic-ref HEAD >actual &&
+	test_cmp expect actual &&
+	echo "$A" >expect &&
+	git rev-parse refs/heads/target1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'fails with duplicate ref update via symref' '
+	git branch target2 $A &&
+	git symbolic-ref refs/heads/symref2 refs/heads/target2 &&
+	cat >stdin <<-EOF &&
+	update refs/heads/target2 $C
+	update refs/heads/symref2 $B
+	EOF
+	test_must_fail git update-ref --stdin <stdin 2>err &&
+	grep "fatal: multiple updates for '\''refs/heads/target2'\'' (including one via symref .refs/heads/symref2.) are not allowed" err &&
+	echo "refs/heads/target2" >expect &&
+	git symbolic-ref refs/heads/symref2 >actual &&
+	test_cmp expect actual &&
+	echo "$A" >expect &&
+	git rev-parse refs/heads/target2 >actual &&
+	test_cmp expect actual
+'
+
 run_with_limited_open_files () {
 	(ulimit -n 32 && "$@")
 }