t/{t5541,lib-httpd}: replace problematic '!()' notation with test_must_fail

diff --git a/t/t3405-rebase-malformed.sh b/t/t3405-rebase-malformed.sh
index e4e2e649ed03394f623eb0d135815c3d570a3186..e5ad67c643ffee9b79fce813673732faa950714f 100755 (executable)
--- a/t/t3405-rebase-malformed.sh
+++ b/t/t3405-rebase-malformed.sh
@@ -41,8 +41,8 @@ test_expect_success rebase '
        git rebase master side &&
        git cat-file commit HEAD | sed -e "1,/^\$/d" >F1 &&
 
-       diff -u F0 F1 &&
-       diff -u F F0
+       test_cmp F0 F1 &&
+       test_cmp F F0
 '
 
 test_done