commit: factor out set_merge_remote_desc()

Export a helper function for allocating, populating and attaching a
merge_remote_desc to a commit.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit.c

@@ -1576,6 +1576,16 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	return result;
 }
 
+void set_merge_remote_desc(struct commit *commit,
+			   const char *name, struct object *obj)
+{
+	struct merge_remote_desc *desc;
+	desc = xmalloc(sizeof(*desc));
+	desc->obj = obj;
+	desc->name = xstrdup(name);
+	commit->util = desc;
+}
+
 struct commit *get_merge_parent(const char *name)
 {
 	struct object *obj;
@@ -1585,13 +1595,8 @@ struct commit *get_merge_parent(const char *name)
 		return NULL;
 	obj = parse_object(oid.hash);
 	commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
-	if (commit && !commit->util) {
-		struct merge_remote_desc *desc;
-		desc = xmalloc(sizeof(*desc));
-		desc->obj = obj;
-		desc->name = xstrdup(name);
-		commit->util = desc;
-	}
+	if (commit && !commit->util)
+		set_merge_remote_desc(commit, name, obj);
 	return commit;
 }
 

commit.h

@@ -359,6 +359,8 @@ struct merge_remote_desc {
 	const char *name;
 };
 #define merge_remote_util(commit) ((struct merge_remote_desc *)((commit)->util))
+extern void set_merge_remote_desc(struct commit *commit,
+				  const char *name, struct object *obj);
 
 /*
  * Given "name" from the command line to merge, find the commit object