[PATCH] write_sha1_to_fd()

Add write_sha1_to_fd(), which writes an object to a file descriptor. This
includes support for unpacking it and recompressing it.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/cache.h b/cache.h
index 84d43d3..4d2bde5 100644
--- a/cache.h
+++ b/cache.h
@@ -185,6 +185,7 @@
 extern int read_tree(void *buffer, unsigned long size, int stage);
 
 extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
+extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
 
 extern int has_sha1_pack(const unsigned char *sha1);
 extern int has_sha1_file(const unsigned char *sha1);