Reworked read-tree.

[Junio C Hamano <junkio@cox.net>]

Daniel, I do not know what your current status is, but I think
you need something like this.

I was scratching my head figuring out why it passes all the t/
tests but couldn't do a simple 'git-read-tree HEAD'.

---
diff --git a/tree.c b/tree.c
--- a/tree.c
+++ b/tree.c
@@ -224,10 +224,12 @@ struct tree *parse_tree_indirect(const u
 		if (obj->type == tree_type)
 			return (struct tree *) obj;
 		else if (obj->type == commit_type)
-			return ((struct commit *) obj)->tree;
+			obj = (struct object *)(((struct commit *) obj)->tree);
 		else if (obj->type == tag_type)
-			obj = ((struct tag *) obj)->tagged;
+			obj = deref_tag(obj);
 		else
 			return NULL;
+		if (!obj->parsed)
+			parse_object(obj->sha1);
 	} while (1);
 }