- Patch #306027 by catch et al: user_modules_uninstalled() is missing.

modules/user/user.admin.inc

@@ -952,7 +952,9 @@ function user_modules_installed($modules) {
 function user_modules_uninstalled($modules) {
   $permissions = array();
   foreach ($modules as $module) {
-    $permissions = array_merge($permissions, array_keys(module_invoke($module, 'permission')));
+    if (drupal_function_exists($module . '_permission')) {
+      $permissions = array_merge($permissions, array_keys(module_invoke($module, 'permission')));
+    }
   }
   if (!empty($permissions)) {
     db_delete('role_permission')