test_must_fail git rev-parse --verify -q $c
'
+test_expect_success 'stdin -z create ref fails when ref exists' '
+ git update-ref $c $m &&
+ git rev-parse "$c" >expect &&
+ printf $F "create $c" "$m~1" >stdin &&
+ test_must_fail git update-ref -z --stdin <stdin 2>err &&
+ grep "fatal: Cannot lock the ref '"'"'$c'"'"'" err &&
+ git rev-parse "$c" >actual &&
+ test_cmp expect actual
+'
+
test_expect_success 'stdin -z create ref fails with bad new value' '
+ git update-ref -d "$c" &&
printf $F "create $c" "does-not-exist" >stdin &&
test_must_fail git update-ref -z --stdin <stdin 2>err &&
grep "fatal: create $c: invalid <newvalue>: does-not-exist" err &&