symfony
diff --git a/‎src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
+8-7Lines changed: 8 additions & 7 deletions b/‎src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php
+8-7Lines changed: 8 additions & 7 deletions
@@ -13,6 +13,7 @@
 
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
 use Symfony\Component\HttpKernel\Log\DebugLoggerInterface;
@@ -31,7 +32,6 @@ class ExceptionListener implements EventSubscriberInterface
 {
     protected $controller;
     protected $logger;
-    private $exceptionHasBeenThrown = false;
 
     public function __construct($controller, LoggerInterface $logger = null)
     {
@@ -43,7 +43,7 @@ public function onKernelException(GetResponseForExceptionEvent $event)
     {
         $exception = $event->getException();
         $request = $event->getRequest();
-        $this->exceptionHasBeenThrown = true;
+        $eventDispatcher = func_get_arg(2);
 
         $this->logException($exception, sprintf('Uncaught PHP Exception %s: "%s" at %s line %s', get_class($exception), $exception->getMessage(), $exception->getFile(), $exception->getLine()));
 
@@ -70,20 +70,21 @@ public function onKernelException(GetResponseForExceptionEvent $event)
         }
 
         $event->setResponse($response);
-    }
 
-    public function onKernelResponse(FilterResponseEvent $event)
-    {
-        if ($this->exceptionHasBeenThrown) {
+        $cspRemovalListener = function (FilterResponseEvent $event) use (&$cspRemovalListener, $eventDispatcher) {
             $event->getResponse()->headers->remove('Content-Security-Policy');
+            $eventDispatcher->removeListener(KernelEvents::RESPONSE, $cspRemovalListener);
+        };
+
+        if ($eventDispatcher instanceof EventDispatcherInterface) {
+            $eventDispatcher->addListener(KernelEvents::RESPONSE, $cspRemovalListener, -128);
         }
     }
 
     public static function getSubscribedEvents()
     {
         return array(
             KernelEvents::EXCEPTION => array('onKernelException', -128),
-            KernelEvents::RESPONSE => array('onKernelResponse', -128),
         );
     }