Issue #1803338 by chx, katbailey, jthorson, Crell: Fixed 403 and 404 pages...

Issue #1803338 by chx, katbailey, jthorson, Crell: Fixed 403 and 404 pages call error_log() cluttering server error logs.

core/lib/Drupal/Core/CoreBundle.php

@@ -119,7 +119,7 @@ public function build(ContainerBuilder $container) {
     $container->register('request_close_subscriber', 'Drupal\Core\EventSubscriber\RequestCloseSubscriber')
       ->addTag('kernel.event_subscriber');
     $container->register('config_global_override_subscriber', '\Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber');
-    $container->register('exception_listener', 'Symfony\Component\HttpKernel\EventListener\ExceptionListener')
+    $container->register('exception_listener', 'Drupal\Core\EventSubscriber\ExceptionListener')
       ->addTag('kernel.event_subscriber')
       ->addArgument(new Reference('service_container'))
       ->setFactoryClass('Drupal\Core\ExceptionController')

core/lib/Drupal/Core/EventSubscriber/ExceptionListener.php

+<?php
+
+/*
+ * @file
+ * Definition of Drupal\Core\EventSubscriber\ExceptionListener.
+ */
+
+namespace Drupal\Core\EventSubscriber;
+
+use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Component\HttpKernel\Exception\FlattenException;
+use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Override of Symfony EventListener class to kill 403 and 404 from server logs.
+ *
+ * This is mostly a copy of Symfony's ExceptionListener but it doesn't have a
+ * $logger property as we are not currently using a logger. The class from
+ * Symfony will, in the absense of a logger, call error_log() on every http
+ * exception.
+ *
+ * @todo Remove this class once we introduce a logger.
+ *
+ * @see http://drupal.org/node/1803338
+ */
+class ExceptionListener implements EventSubscriberInterface {
+  private $controller;
+
+  public function __construct($controller) {
+    $this->controller = $controller;
+  }
+
+  public function onKernelException(GetResponseForExceptionEvent $event) {
+    static $handling;
+
+    if ($handling) {
+      return FALSE;
+    }
+
+    $handling = TRUE;
+
+    $exception = $event->getException();
+    $request = $event->getRequest();
+    // Do not put a line in the server logs for every HTTP error.
+    if (!$exception instanceof HttpExceptionInterface || $exception->getStatusCode() >= 500) {
+        error_log(sprintf('Uncaught PHP Exception %s: "%s" at %s line %s', get_class($exception), $exception->getMessage(), $exception->getFile(), $exception->getLine()));
+    }
+
+    $attributes = array(
+      '_controller' => $this->controller,
+      'exception'   => FlattenException::create($exception),
+      'logger'      => NULL,
+      'format'      => $request->getRequestFormat(),
+    );
+
+    $request = $request->duplicate(NULL, NULL, $attributes);
+    $request->setMethod('GET');
+
+    try {
+      $response = $event->getKernel()->handle($request, HttpKernelInterface::SUB_REQUEST, TRUE);
+    }
+    catch (\Exception $e) {
+      $message = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($e), $e->getMessage());
+      error_log($message);
+      // Set handling to false otherwise it won't be able to handle further
+      // exceptions.
+      $handling = FALSE;
+      return;
+    }
+
+    $event->setResponse($response);
+    $handling = FALSE;
+  }
+
+  public static function getSubscribedEvents() {
+    return array(
+      KernelEvents::EXCEPTION => array('onKernelException', -128),
+    );
+  }
+}

core/lib/Drupal/Core/ExceptionController.php

@@ -12,9 +12,8 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpFoundation\JsonResponse;
-use Drupal\Core\HttpKernel;
 use Symfony\Component\HttpKernel\Exception\FlattenException;
-use Symfony\Component\HttpKernel\EventListener\ExceptionListener;
+use Drupal\Core\EventSubscriber\ExceptionListener;
 
 /**
  * This controller handles HTTP errors generated by the routing system.