[WebProfilerBundle] Normalize whitespace in exceptions passed in headers

If an exception was thrown with line separators in its message the
WebProfiler would cause an exception by passing it through unsanitized
into the X-Debug-Error HTTP header. This commit fixes that by replacing
all whitespace sequences with a single space in the header.

src/Symfony/Bundle/WebProfilerBundle/EventListener/WebDebugToolbarListener.php

@@ -68,7 +68,7 @@ class WebDebugToolbarListener implements EventSubscriberInterface
                     $this->urlGenerator->generate('_profiler', array('token' => $response->headers->get('X-Debug-Token')))
                 );
             } catch (\Exception $e) {
-                $response->headers->set('X-Debug-Error', get_class($e).': '.$e->getMessage());
+                $response->headers->set('X-Debug-Error', get_class($e).': '.preg_replace('/\s+/', ' ', $e->getMessage()));
             }
         }
 

src/Symfony/Bundle/WebProfilerBundle/Tests/EventListener/WebDebugToolbarListenerTest.php

@@ -228,6 +228,27 @@ class WebDebugToolbarListenerTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('Exception: foo', $response->headers->get('X-Debug-Error'));
     }
 
+    public function testThrowingErrorCleanup()
+    {
+        $response = new Response();
+        $response->headers->set('X-Debug-Token', 'xxxxxxxx');
+
+        $urlGenerator = $this->getUrlGeneratorMock();
+        $urlGenerator
+            ->expects($this->once())
+            ->method('generate')
+            ->with('_profiler', array('token' => 'xxxxxxxx'))
+            ->will($this->throwException(new \Exception("This\nmultiline\r\ntabbed text should\tcome out\r on\n \ta single plain\r\nline")))
+        ;
+
+        $event = new FilterResponseEvent($this->getKernelMock(), $this->getRequestMock(), HttpKernelInterface::MASTER_REQUEST, $response);
+
+        $listener = new WebDebugToolbarListener($this->getTwigMock(), false, WebDebugToolbarListener::ENABLED, 'bottom', $urlGenerator);
+        $listener->onKernelResponse($event);
+
+        $this->assertEquals('Exception: This multiline tabbed text should come out on a single plain line', $response->headers->get('X-Debug-Error'));
+    }
+
     protected function getRequestMock($isXmlHttpRequest = false, $requestFormat = 'html', $hasSession = true)
     {
         $request = $this->getMock(