fixed a bug in Response content-type auto-detection

Without this patch, if you call __toString() on a Response,
the content-type auto-detection would never be trigerred
as __toString() changes the default content-type.

src/Symfony/Bundle/FrameworkBundle/Resources/config/web.xml

@@ -34,6 +34,7 @@
 
         <service id="response_listener" class="%response_listener.class%">
             <tag name="kernel.listener" event="core.response" method="filter" />
+            <argument>%kernel.charset%</argument>
         </service>
 
         <service id="exception_listener" class="%exception_listener.class%">

src/Symfony/Component/HttpFoundation/Response.php

@@ -27,7 +27,7 @@ class Response
     protected $version;
     protected $statusCode;
     protected $statusText;
-    protected $charset = 'UTF-8';
+    protected $charset;
 
     static public $statusTexts = array(
         100 => 'Continue',
@@ -98,7 +98,7 @@ class Response
         $content = '';
 
         if (!$this->headers->has('Content-Type')) {
-            $this->headers->set('Content-Type', 'text/html; charset='.$this->charset);
+            $this->headers->set('Content-Type', 'text/html; charset='.(null === $this->charset ? 'UTF-8' : $this->charset));
         }
 
         // status
@@ -130,7 +130,7 @@ class Response
     public function sendHeaders()
     {
         if (!$this->headers->has('Content-Type')) {
-            $this->headers->set('Content-Type', 'text/html; charset='.$this->charset);
+            $this->headers->set('Content-Type', 'text/html; charset='.(null === $this->charset ? 'UTF-8' : $this->charset));
         }
 
         // status

src/Symfony/Component/HttpKernel/ResponseListener.php

@@ -23,6 +23,13 @@ use Symfony\Component\HttpFoundation\Response;
  */
 class ResponseListener
 {
+    protected $charset;
+
+    public function __construct($charset)
+    {
+        $this->charset = $charset;
+    }
+
     /**
      * Filters the Response.
      *
@@ -31,7 +38,15 @@ class ResponseListener
      */
     public function filter(EventInterface $event, Response $response)
     {
-        if (HttpKernelInterface::MASTER_REQUEST !== $event->get('request_type') || $response->headers->has('Content-Type')) {
+        if (HttpKernelInterface::MASTER_REQUEST !== $event->get('request_type')) {
+            return $response;
+        }
+
+        if (null === $response->getCharset()) {
+            $response->setCharset($this->charset);
+        }
+
+        if ($response->headers->has('Content-Type')) {
             return $response;
         }
 

tests/Symfony/Tests/Component/HttpKernel/ResponseListenerTest.php

@@ -59,7 +59,7 @@ class ResponseListenerTest extends \PHPUnit_Framework_TestCase
     protected function getDispatcher()
     {
         $dispatcher = new EventDispatcher();
-        $listener = new ResponseListener();
+        $listener = new ResponseListener('UTF-8');
         $dispatcher->connect('core.response', array($listener, 'filter'));
 
         return $dispatcher;