PHP/Core

* enforced v7.1 compliance, preparations for v7.2
 * removed deprecated usage of each()
 * prefer array deconstruction via [] instead of calling list()
 * try to catch failed session_start()
 * prefer ... - Token instead of calling func_get_args() func_num_args()
 * enforce return types in AjaxHandler
 * revision push

includes/kernel.php

@@ -221,7 +221,12 @@ if (!CLI)
 
     session_set_cookie_params(15 * YEAR, '/', '', $secure, true);
     session_cache_limiter('private');
-    session_start();
+    if (!session_start())
+    {
+        trigger_error('failed to start session', E_USER_ERROR);
+        exit;
+    }
+
     if (!empty($AoWoWconf['aowow']) && User::init())
         User::save();                                       // save user-variables in session