make getDisplayNames optional feature for Group Backends, fall back to internal names

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/group.php b/lib/group.php
index 88f0a2a032c..d1a830730b7 100644
--- a/lib/group.php
+++ b/lib/group.php
@@ -294,7 +294,13 @@ class OC_Group {
 	public static function displayNamesInGroup($gid, $search = '', $limit = -1, $offset = 0) {
 		$displayNames=array();
 		foreach(self::$_usedBackends as $backend) {
-			$displayNames = array_merge($backend->displayNamesInGroup($gid, $search, $limit, $offset), $displayNames);
+			if($backend->implementsActions(OC_GROUP_BACKEND_GET_DISPLAYNAME)) {
+				$displayNames = array_merge($backend->displayNamesInGroup($gid, $search, $limit, $offset), $displayNames);
+			} else {
+				$users = $backend->usersInGroup($gid, $search, $limit, $offset);
+				$names = array_combine($users, $users);
+				$displayNames = array_merge($names, $displayNames);
+			}
 		}
 		return $displayNames;
 	}