--name-only, --name-status, --check and -s are mutually exclusive

Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff.c

@@ -1433,6 +1433,19 @@ void diff_setup(struct diff_options *options)
 
 int diff_setup_done(struct diff_options *options)
 {
+	int count = 0;
+
+	if (options->output_format & DIFF_FORMAT_NAME)
+		count++;
+	if (options->output_format & DIFF_FORMAT_NAME_STATUS)
+		count++;
+	if (options->output_format & DIFF_FORMAT_CHECKDIFF)
+		count++;
+	if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
+		count++;
+	if (count > 1)
+		die("--name-only, --name-status, --check and -s are mutually exclusive");
+
 	if ((options->find_copies_harder &&
 	     options->detect_rename != DIFF_DETECT_COPY) ||
 	    (0 <= options->rename_limit && !options->detect_rename))