Add output_prefix_length to diff_options

Add output_prefix_length to diff_options. Initialize the value to 0 and only
set it when graph.c:diff_output_prefix_callback() is called.

Signed-off-by: Lucian Poston <lucian.poston@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/diff.h b/diff.h
index cb68743..19d762f 100644
--- a/diff.h
+++ b/diff.h
@@ -150,6 +150,7 @@ struct diff_options {
 	diff_format_fn_t format_callback;
 	void *format_callback_data;
 	diff_prefix_fn_t output_prefix;
+	int output_prefix_length;
 	void *output_prefix_data;
 };