[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>
diff --git a/cache.h b/cache.h
index dbde95a..f14a4ce 100644
--- a/cache.h
+++ b/cache.h
@@ -319,6 +319,8 @@
 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);