commit ce47a424491a18ce7fec45cd7b3ab08f568c90d6
from: Stefan Sperling <stsp@stsp.name>
date: Sun Jul 22 11:52:36 2018 UTC

treat double-linking to same child in commit graph as no-op

commit - e0d42f609a25f032fe7b71d540dc343013c0a92b
commit + ce47a424491a18ce7fec45cd7b3ab08f568c90d6
blob - e973de6181ecc3d2fe1b5be6836948d252ec8279
blob + 2c10f94ec0af1f680f3797b95bbf57ad19ef579d
--- lib/commit_graph.c
+++ lib/commit_graph.c
@@ -307,10 +307,10 @@ add_node(struct got_commit_graph_node **new_node,
 		if (got_object_id_cmp(commit_id, &child_node->id) == 0)
 			return got_error(GOT_ERR_BAD_OBJ_ID);
 
-		/* Prevent double-linking to the same child. */
+		/* Prevent double-linking to the same child (treat as no-op). */
 		SIMPLEQ_FOREACH(cid, &node->child_ids, entry) {
 			if (got_object_id_cmp(cid->id, &child_node->id) == 0)
-				return got_error(GOT_ERR_BAD_OBJ_ID);
+				return NULL;
 		}
 
 		err = add_vertex(&node->child_ids, &child_node->id);