diff --git a/core/lib/Drupal/Core/EventSubscriber/AccessSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/AccessSubscriber.php
index e6f6eb8..553fb3c 100644
--- a/core/lib/Drupal/Core/EventSubscriber/AccessSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/AccessSubscriber.php
@@ -52,7 +52,16 @@ public function onKernelRequestAccessCheck(GetResponseEvent $event) {
       return;
     }
 
-    $access = $this->accessManager->check($request->attributes->get(RouteObjectInterface::ROUTE_OBJECT), $request);
+    // Wrap this in a try/catch to ensure the '_controller_request' attribute
+    // can always be removed.
+    try {
+      $access = $this->accessManager->check($request->attributes->get(RouteObjectInterface::ROUTE_OBJECT), $request);
+    }
+    catch (\Exception $e) {
+      $request->attributes->remove('_controller_request');
+      throw $e;
+    }
+
     if (!$access) {
       throw new AccessDeniedHttpException();
     }
diff --git a/core/lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php b/core/lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php
index 42261cb..43071be 100644
--- a/core/lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php
+++ b/core/lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php
@@ -10,7 +10,10 @@
 use Symfony\Component\Routing\Route;
 
 /**
- * Class RouteProcessorManager.
+ * Route processor manager.
+ *
+ * Holds an array of route processor objects and uses them to sequentially
+ * process an outbound route, in order of processor priority.
  */
 class RouteProcessorManager implements OutboundRouteProcessorInterface {
 
diff --git a/core/tests/Drupal/Tests/Core/Access/CsrfAccessCheckTest.php b/core/tests/Drupal/Tests/Core/Access/CsrfAccessCheckTest.php
index 2b08b97..bfe40a3 100644
--- a/core/tests/Drupal/Tests/Core/Access/CsrfAccessCheckTest.php
+++ b/core/tests/Drupal/Tests/Core/Access/CsrfAccessCheckTest.php
@@ -16,6 +16,9 @@
 /**
  * Tests the CSRF access checker..
  *
+ * @group Drupal
+ * @group Access
+ *
  * @see \Drupal\Core\Access\CsrfAccessCheck
  */
 class CsrfAccessCheckTest extends UnitTestCase {
diff --git a/core/tests/Drupal/Tests/Core/Access/RouteProcessorCsrfTest.php b/core/tests/Drupal/Tests/Core/Access/RouteProcessorCsrfTest.php
index 06d0b9c..681df29 100644
--- a/core/tests/Drupal/Tests/Core/Access/RouteProcessorCsrfTest.php
+++ b/core/tests/Drupal/Tests/Core/Access/RouteProcessorCsrfTest.php
@@ -13,6 +13,11 @@
 
 /**
  * Tests the CSRF route processor.
+ *
+ * @see Drupal
+ * @see Routing
+ *
+ * @see \Drupal\Core\Access\RouteProcessorCsrf
  */
 class RouteProcessorCsrfTest extends UnitTestCase {
 
diff --git a/core/tests/Drupal/Tests/Core/RouteProcessor/RouteProcessorManagerTest.php b/core/tests/Drupal/Tests/Core/RouteProcessor/RouteProcessorManagerTest.php
index 498faec..6d23ca6 100644
--- a/core/tests/Drupal/Tests/Core/RouteProcessor/RouteProcessorManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/RouteProcessor/RouteProcessorManagerTest.php
@@ -13,6 +13,11 @@
 
 /**
  * Tests the RouteProcessorManager class.
+ *
+ * @group Drupal
+ * @group Routing
+ *
+ * @see \Drupal\Core\RouteProcessor\RouteProcessorManager
  */
 class RouteProcessorManagerTest extends UnitTestCase {
 
diff --git a/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php b/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
index 0997c2c..d1c59c9 100644
--- a/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
+++ b/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\Settings;
 use Drupal\Core\PathProcessor\PathProcessorAlias;
 use Drupal\Core\PathProcessor\PathProcessorManager;
-use Drupal\Core\RouteProcessor\RouteProcessorManager;
 use Drupal\Core\Routing\UrlGenerator;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\HttpFoundation\Request;
@@ -39,8 +38,20 @@ class UrlGeneratorTest extends UnitTestCase {
    */
   protected $generatorMixedMode;
 
+  /**
+   * The alias manager.
+   *
+   * @var \Drupal\Core\Path\AliasManager|\PHPUnit_Framework_MockObject_MockObject
+   */
   protected $aliasManager;
 
+  /**
+   * The mock route processor manager.
+   *
+   * @var \Drupal\Core\RouteProcessor\RouteProcessorManager|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $routeProcessorManager;
+
   public static function getInfo() {
     return array(
       'name' => 'UrlGenerator',
@@ -116,16 +127,18 @@ function setUp() {
     $processor_manager = new PathProcessorManager();
     $processor_manager->addOutbound($processor, 1000);
 
-    $route_processor_manager = new RouteProcessorManager();
+    $this->routeProcessorManager = $this->getMockBuilder('Drupal\Core\RouteProcessor\RouteProcessorManager')
+      ->disableOriginalConstructor()
+      ->getMock();
 
     $config_factory_stub = $this->getConfigFactoryStub(array('system.filter' => array('protocols' => array('http', 'https'))));
 
-    $generator = new UrlGenerator($provider, $processor_manager, $route_processor_manager, $config_factory_stub, new Settings(array()));
+    $generator = new UrlGenerator($provider, $processor_manager, $this->routeProcessorManager, $config_factory_stub, new Settings(array()));
     $generator->setContext($context);
     $this->generator = $generator;
 
     // Second generator for mixed-mode sessions.
-    $generator = new UrlGenerator($provider, $processor_manager, $route_processor_manager, $config_factory_stub, new Settings(array('mixed_mode_sessions' => TRUE)));
+    $generator = new UrlGenerator($provider, $processor_manager, $this->routeProcessorManager, $config_factory_stub, new Settings(array('mixed_mode_sessions' => TRUE)));
     $generator->setContext($context);
     $this->generatorMixedMode = $generator;
   }
@@ -160,6 +173,11 @@ public function testAliasGeneration() {
     $url = $this->generator->generate('test_1');
     $this->assertEquals('/hello/world', $url);
 
+    $this->routeProcessorManager->expects($this->once())
+      ->method('processOutbound')
+      ->with($this->anything());
+
+
     // Check that the two generate methods return the same result.
     $url_from_route = $this->generator->generateFromRoute('test_1');
     $this->assertEquals($url_from_route, $url);
@@ -174,6 +192,9 @@ public function testAliasGeneration() {
   public function testGetPathFromRouteWithSubdirectory() {
     $this->generator->setBasePath('/test-base-path');
 
+    $this->routeProcessorManager->expects($this->never())
+      ->method('processOutbound');
+
     $path = $this->generator->getPathFromRoute('test_1');
     $this->assertEquals('test/one', $path);
   }
@@ -185,6 +206,10 @@ public function testAliasGenerationWithParameters() {
     $url = $this->generator->generate('test_2', array('narf' => '5'));
     $this->assertEquals('/goodbye/cruel/world', $url);
 
+    $this->routeProcessorManager->expects($this->exactly(3))
+      ->method('processOutbound')
+      ->with($this->anything());
+
     $options = array('fragment' => 'top');
     // Extra parameters should appear in the query string.
     $url = $this->generator->generateFromRoute('test_1', array('zoo' => '5'), $options);
@@ -206,6 +231,9 @@ public function testAliasGenerationWithParameters() {
    * Tests URL generation from route with trailing start and end slashes.
    */
   public function testGetPathFromRouteTrailing() {
+    $this->routeProcessorManager->expects($this->never())
+      ->method('processOutbound');
+
     $path = $this->generator->getPathFromRoute('test_3');
     $this->assertEquals($path, 'test/two');
   }
@@ -217,6 +245,10 @@ public function testAbsoluteURLGeneration() {
     $url = $this->generator->generate('test_1', array(), TRUE);
     $this->assertEquals('http://localhost/hello/world', $url);
 
+    $this->routeProcessorManager->expects($this->once())
+      ->method('processOutbound')
+      ->with($this->anything());
+
     $options = array('absolute' => TRUE, 'fragment' => 'top');
     // Extra parameters should appear in the query string.
     $url = $this->generator->generateFromRoute('test_1', array('zoo' => '5'), $options);
@@ -230,6 +262,10 @@ public function testUrlGenerationWithHttpsRequirement() {
     $url = $this->generator->generate('test_4', array(), TRUE);
     $this->assertEquals('https://localhost/test/four', $url);
 
+    $this->routeProcessorManager->expects($this->exactly(2))
+      ->method('processOutbound')
+      ->with($this->anything());
+
     $options = array('absolute' => TRUE, 'https' => TRUE);
     // Mixed-mode sessions are not enabled, so the https option is ignored.
     $url = $this->generator->generateFromRoute('test_1', array(), $options);