dir.c: optionally compute sha-1 of a .gitignore file

This is not used anywhere yet. But the goal is to compare quickly if a
.gitignore file has changed when we have the SHA-1 of both old (cached
somewhere) and new (from index or a tree) versions.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/dir.h b/dir.h
index 6c45e9d4b9..cdca71b3b0 100644
--- a/dir.h
+++ b/dir.h
@@ -73,6 +73,12 @@ struct exclude_list_group {
 	struct exclude_list *el;
 };
 
+struct sha1_stat {
+	struct stat_data stat;
+	unsigned char sha1[20];
+	int valid;
+};
+
 struct dir_struct {
 	int nr, alloc;
 	int ignored_nr, ignored_alloc;