'
+test_expect_success 'no diff with -diff' '
+ echo >.gitattributes "file -diff" &&
+ git diff | grep Binary
+'
+
+echo NULZbetweenZwords | perl -pe 'y/Z/\000/' > file
+
+test_expect_success 'force diff with "diff"' '
+ echo >.gitattributes "file diff" &&
+ git diff >actual &&
+ test_cmp "$TEST_DIRECTORY"/t4020/diff.NUL actual
+'
+
test_done