queue: handle pkgconf_pkg_verify_dependency failure while flattening

libpkgconf/queue.c

@@ -51,7 +51,7 @@ pkgconf_queue_push(pkgconf_list_t *list, const char *package)
 	pkgconf_queue_t *pkgq = calloc(sizeof(pkgconf_queue_t), 1);
 
 	pkgq->package = strdup(package);
-	pkgconf_node_insert_tail(&pkgq->iter, pkgq, list);
+	pkgconf_node_insert(&pkgq->iter, pkgq, list);
 }
 
 /*
@@ -113,6 +113,9 @@ pkgconf_queue_collect_dependents(pkgconf_client_t *client, pkgconf_pkg_t *pkg, v
 	pkgconf_node_t *node;
 	pkgconf_pkg_t *world = data;
 
+	if (pkg == world)
+		return;
+
 	PKGCONF_FOREACH_LIST_ENTRY(pkg->required.head, node)
 	{
 		pkgconf_dependency_t *flattened_dep;
@@ -153,6 +156,9 @@ flatten_dependency_set(pkgconf_client_t *client, pkgconf_list_t *list)
 		pkgconf_dependency_t *dep = node->data;
 		pkgconf_pkg_t *pkg = pkgconf_pkg_verify_dependency(client, dep, NULL);
 
+		if (pkg == NULL)
+			continue;
+
 		if (pkg->serial == client->serial)
 			continue;