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

diff --git a/t/t4038-diff-combined.sh b/t/t4038-diff-combined.sh
index 7584efa36b06effd9005b8ebcc6afecec07e424b..40277c77aad5f2d9533e6822da3380bb49621e59 100755 (executable)
--- a/t/t4038-diff-combined.sh
+++ b/t/t4038-diff-combined.sh
@@ -81,4 +81,12 @@ test_expect_success 'check combined output (2)' '
        verify_helper sidesansone
 '
 
+test_expect_success 'diagnose truncated file' '
+       >file &&
+       git add file &&
+       git commit --amend -C HEAD &&
+       git show >out &&
+       grep "diff --cc file" out
+'
+
 test_done