tree-walk: convert fill_tree_descriptor() to object_id

All callers of fill_tree_descriptor() have been converted to object_id
already, so convert that function as well.  As a nice side-effect we get
rid of NULL checks in tree-diff.c, as fill_tree_descriptor() already
does them for us.

Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/tree-walk.c b/tree-walk.c
index 6a42e402b0..c99309069a 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -78,15 +78,16 @@ int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned l
 	return result;
 }
 
-void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
+void *fill_tree_descriptor(struct tree_desc *desc, const struct object_id *oid)
 {
 	unsigned long size = 0;
 	void *buf = NULL;
 
-	if (sha1) {
-		buf = read_object_with_reference(sha1, tree_type, &size, NULL);
+	if (oid) {
+		buf = read_object_with_reference(oid->hash, tree_type, &size,
+						 NULL);
 		if (!buf)
-			die("unable to read tree %s", sha1_to_hex(sha1));
+			die("unable to read tree %s", oid_to_hex(oid));
 	}
 	init_tree_desc(desc, buf, size);
 	return buf;