Do not assume we have a Logger in ErrorHandler, fixes #666

src/Monolog/ErrorHandler.php

@@ -174,6 +174,7 @@ class ErrorHandler
                 array('code' => $lastError['type'], 'message' => $lastError['message'], 'file' => $lastError['file'], 'line' => $lastError['line'])
             );
 
+            if ($this->logger instanceof Logger) {
                 foreach ($this->logger->getHandlers() as $handler) {
                     if ($handler instanceof AbstractHandler) {
                         $handler->close();
@@ -181,6 +182,7 @@ class ErrorHandler
                 }
             }
         }
+    }
 
     private static function codeToString($code)
     {