diff --git a/core/lib/Drupal/Core/Routing/RequestHelper.php b/core/lib/Drupal/Core/Routing/RequestHelper.php
index b060e47..25138bb 100644
--- a/core/lib/Drupal/Core/Routing/RequestHelper.php
+++ b/core/lib/Drupal/Core/Routing/RequestHelper.php
@@ -49,6 +49,11 @@ class RequestHelper {
    */
   public static function duplicate(Request $original_request, $uri, $method = 'GET', $parameters = array(), array $query = NULL, array $post = NULL, array $attributes = NULL, array $cookies = NULL, array $files = NULL, array $server = NULL) {
     $request = $original_request->duplicate($query, $post, $attributes, $cookies, $files, $server);
+    // Request::duplicate() clones the attributes, but we want to re-populate
+    // them from scratch when using this method.
+    if (empty($attributes)) {
+      $request->attributes->replace(array());
+    }
 
     $server = array();
 
diff --git a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
index f93cb6f..c3b3200 100644
--- a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
+++ b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
@@ -163,8 +163,8 @@ public function build(array $attributes) {
             //   https://drupal.org/node/2076085.
             $title = str_replace(array('-', '_'), ' ', Unicode::ucfirst(end($path_elements)));
           }
-          // @todo Replace with a #type => link render element or use the link
-          // generator.
+          // @todo Replace with a #type => link render element so that the alter
+          // hook can work with the actual data.
           $links[] = l($title, $route_request->attributes->get('_system_path'));
         }
       }