[Debug] prevent infinite loop with faulty exception handlers

nicolas-grekas · nicolas-grekas · commit 4a8a18e2fdf4 · 2018-01-10T19:08:00.000+01:00
diff --git a/src/Symfony/Component/Debug/ErrorHandler.php b/src/Symfony/Component/Debug/ErrorHandler.php
@@ -561,16 +561,22 @@ public static function handleFatalError(array $error = null)
 
         $handler = self::$reservedMemory = null;
         $handlers = array();
+        $previousHandler = null;
+        $previousHandlerLimit = 10;
 
         while (!is_array($handler) || !$handler[0] instanceof self) {
             $handler = set_exception_handler('var_dump');
             restore_exception_handler();
 
+            if ($handler === $previousHandler && !--$previousHandlerLimit) {
+                $handler = null;
+            }
             if (!$handler) {
                 break;
             }
             restore_exception_handler();
             array_unshift($handlers, $handler);
+            $previousHandler = $handler;
         }
         foreach ($handlers as $h) {
             set_exception_handler($h);
