Allow git-diff exit with codes similar to diff(1)

This introduces a new command-line option: --exit-code. The diff
programs will return 1 for differences, return 0 for equality, and
something else for errors.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/diff.h b/diff.h
index 4b435e8b19..d13fc89768 100644
--- a/diff.h
+++ b/diff.h
@@ -56,7 +56,8 @@ struct diff_options {
 		 silent_on_remove:1,
 		 find_copies_harder:1,
 		 color_diff:1,
-		 color_diff_words:1;
+		 color_diff_words:1,
+		 exit_with_status:1;
 	int context;
 	int break_opt;
 	int detect_rename;
@@ -71,6 +72,8 @@ struct diff_options {
 	const char *msg_sep;
 	const char *stat_sep;
 	long xdl_opts;
+	/* 0 - no differences; only meaningful if exit_with_status set */
+	int has_changes;
 
 	int stat_width;
 	int stat_name_width;