t7610-mergetool: use test_cmp instead of test $(cat file) = $txt

diff --git a/t/t7401-submodule-summary.sh b/t/t7401-submodule-summary.sh
index 1cd12b38c53c7fdfedb937151d961527aa990dbd..9bc841d085ee74cbc4a103b3c2f07c7e4b86e82d 100755 (executable)
--- a/t/t7401-submodule-summary.sh
+++ b/t/t7401-submodule-summary.sh
@@ -300,7 +300,7 @@ test_expect_success 'should not fail in an empty repo' "
        git init xyzzy &&
        cd xyzzy &&
        git submodule summary >output 2>&1 &&
-       test_cmp output /dev/null
+       test_must_be_empty output
 "
 
 test_done