[PATCH] Add function to read an index file from an arbitrary filename.

Note that the pack file has to be in the usual location if it gets
installed later.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -319,6 +319,8 @@ extern int get_ack(int fd, unsigned char *result_sha1);
 extern struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match);
 
 extern struct packed_git *parse_pack_index(unsigned char *sha1);
+extern struct packed_git *parse_pack_index_file(unsigned char *sha1, 
+						char *idx_path);
 
 extern void prepare_packed_git(void);
 extern void install_packed_git(struct packed_git *pack);

sha1_file.c

@@ -475,13 +475,19 @@ struct packed_git *add_packed_git(char *path, int path_len)
 }
 
 struct packed_git *parse_pack_index(unsigned char *sha1)
+{
+	char *path = sha1_pack_index_name(sha1);
+	return parse_pack_index_file(sha1, path);
+}
+
+struct packed_git *parse_pack_index_file(unsigned char *sha1, char *idx_path)
 {
 	struct packed_git *p;
 	unsigned long idx_size;
 	void *idx_map;
-	char *path = sha1_pack_index_name(sha1);
+	char *path;
 
-	if (check_packed_git_idx(path, &idx_size, &idx_map))
+	if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
 		return NULL;
 
 	path = sha1_pack_name(sha1);