git-check-attr: Error out if no pathnames are specified

If no pathnames are passed as command-line arguments and the --stdin
option is not specified, fail with the error message "No file
specified".  Add tests of this behavior.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/check-attr.c

@@ -111,8 +111,13 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 	}
 
 	/* Check file argument(s): */
-	if (stdin_paths && filei < argc)
-		error_with_usage("Can't specify files with --stdin");
+	if (stdin_paths) {
+		if (filei < argc)
+			error_with_usage("Can't specify files with --stdin");
+	} else {
+		if (filei >= argc)
+			error_with_usage("No file specified");
+	}
 
 	check = xcalloc(cnt, sizeof(*check));
 	for (i = 0; i < cnt; i++) {

t/t0003-attributes.sh

@@ -46,6 +46,8 @@ test_expect_success 'command line checks' '
 
 	test_must_fail git check-attr &&
 	test_must_fail git check-attr -- &&
+	test_must_fail git check-attr test &&
+	test_must_fail git check-attr test -- &&
 	test_must_fail git check-attr -- f &&
 	echo "f" | test_must_fail git check-attr --stdin &&
 	echo "f" | test_must_fail git check-attr --stdin -- f &&