Fixing default user list order see #7441

main/inc/lib/course.lib.php

@@ -1380,6 +1380,13 @@ class CourseManager
         $course_code = Database::escape_string($course_code);
         $where = array();
         
+        if (empty($order_by)) {
+            $order_by = 'user.lastname, user.firstname';
+            if (api_is_western_name_order()) {
+                $order_by = 'user.firstname, user.lastname';
+            }
+        }
+
         // if the $order_by does not contain 'ORDER BY' we have to check if it is a valid field that can be sorted on
         if (!strstr($order_by,'ORDER BY')) {
             if (!empty($order_by)) {