userdiff: add a builtin pattern for dts files

diff --git a/t/t4019-diff-wserror.sh b/t/t4019-diff-wserror.sh
index a5019759bc7593cf8affd8625f61bbd7ab1b9655..c6135c75488ff01797a98e43163e0b0c5e6be169 100755 (executable)
--- a/t/t4019-diff-wserror.sh
+++ b/t/t4019-diff-wserror.sh
@@ -260,7 +260,7 @@ test_expect_success 'trailing empty lines (2)' '
 
        echo "F -whitespace" >.gitattributes &&
        git diff --check >output &&
-       ! test -s output
+       test_must_be_empty output
 
 '