t7508: fix bogus mtime verification

The current `grep`-approach in "--no-optional-locks prevents index
update" may fail e.g. for `out` file contents "1234567890999" [1].
Fix this by using test-lib's new mtime-verification API.

[1] https://lore.kernel.org/git/xmqqczl5hpaq.fsf@gitster.g/T/#u

Signed-off-by: Marc Strapetz <marc.strapetz@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index 05c6c02435d5b99f406470f1cf18acdd0bc9757a..b9efd2613d0f36bab28fe2aa92521f2572024f1a 100755 (executable)
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -1647,13 +1647,11 @@ test_expect_success '"Initial commit" should not be noted in commit template' '
 '
 
 test_expect_success '--no-optional-locks prevents index update' '
-       test-tool chmtime =1234567890 .git/index &&
+       test_set_magic_mtime .git/index &&
        git --no-optional-locks status &&
-       test-tool chmtime --get .git/index >out &&
-       grep ^1234567890 out &&
+       test_is_magic_mtime .git/index &&
        git status &&
-       test-tool chmtime --get .git/index >out &&
-       ! grep ^1234567890 out
+       ! test_is_magic_mtime .git/index
 '
 
 test_done