prevent temporary permissions to be deleted when managing them for one user, re #2158

Merge request studip/studip!2019

app/controllers/resources/resource.php

@@ -1125,6 +1125,8 @@ class Resources_ResourceController extends AuthenticatedController
                 }
             }
 
+            $deleted_permissions = 0;
+            if (!$this->single_user_mode) {
                 //Now we must remove all permissions where the resource_id is given
                 //and where the user_id is not in the $user_ids array which has been
                 //filled above.
@@ -1148,7 +1150,7 @@ class Resources_ResourceController extends AuthenticatedController
                         ]
                     );
                 }
-
+            }
             if (count($errors)) {
                 PageLayout::postError(
                     _('Die folgenden Fehler traten auf beim Speichern der Berechtigungen:'),