[PATCH] Allow reading "symbolic refs" that point to other refs

This extends the ref reading to understand a "symbolic ref": a ref file
that starts with "ref: " and points to another ref file, and thus
introduces the notion of ref aliases.

This is in preparation of allowing HEAD to eventually not be a symlink,
but one of these symbolic refs instead.

[jc: Linus originally required the prefix to be "ref: " five bytes
 and nothing else, but I changed it to allow and strip any number of
 leading whitespaces to match what update-ref.c does.]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index b8e3d9bfac..958c96e14d 100644
--- a/cache.h
+++ b/cache.h
@@ -229,6 +229,7 @@ extern int has_pack_index(const unsigned char *sha1);
 extern int get_sha1(const char *str, unsigned char *sha1);
 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
+extern int read_ref(const char *filename, unsigned char *sha1);
 
 /* General helper functions */
 extern void usage(const char *err) NORETURN;