diff --git a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
index 26937ee..c8ccc34 100644
--- a/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
+++ b/core/lib/Drupal/Core/Menu/ContextualLinkManager.php
@@ -18,7 +18,7 @@
 use Drupal\Core\Plugin\Factory\ContainerFactory;
 
 /**
- * Defines a plugin manager to deal with contextual links.
+ * Defines a contextual link plugin manager to deal with contextual links.
  *
  * @see \Drupal\Core\Menu\ContextualLinkInterface
  */
@@ -39,7 +39,7 @@ class ContextualLinkManager extends DefaultPluginManager {
     // The default link options.
     'options' => array(),
     // The weight of the link.
-    'weight' => NULL,
+    'weight' => 0,
     // Default class for contextual link implementations.
     'class' => '\Drupal\Core\Menu\ContextualLinkDefault',
     // The plugin id. Set by the plugin system based on the top-level YAML key.
@@ -80,13 +80,14 @@ public function __construct(ControllerResolverInterface $controller_resolver, Mo
    */
   public function processDefinition(&$definition, $plugin_id) {
     parent::processDefinition($definition, $plugin_id);
+
      // If there is no route name, this is a broken definition.
     if (empty($definition['route_name'])) {
-      throw new PluginException(sprintf('Plugin (%s) definition must include "route_name"', $plugin_id));
+      throw new PluginException(sprintf('Plugin (%s) definition must include "route_name".', $plugin_id));
     }
      // If there is no group name, this is a broken definition.
     if (empty($definition['group'])) {
-      throw new PluginException(sprintf('Plugin (%s) definition must include "group"', $plugin_id));
+      throw new PluginException(sprintf('Plugin (%s) definition must include "group".', $plugin_id));
     }
   }
 
@@ -97,7 +98,7 @@ public function processDefinition(&$definition, $plugin_id) {
    *   The group name.
    *
    * @return array
-   *   A list of contextual links plugin definitions, which should be shown.
+   *   A list of contextual links plugin definitions.
    */
   public function getContextualLinkPluginsByGroup($group_name) {
     if ($cache = $this->cacheBackend->get($this->cacheKey . ':' . $group_name)) {
@@ -116,7 +117,7 @@ public function getContextualLinkPluginsByGroup($group_name) {
   }
 
   /**
-   * Gets the contextual links prepared as expected by theme_links.
+   * Gets the contextual links prepared as expected by theme_links().
    *
    * @param string $group_name
    *   The group name.
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index 37f6e07..fc460d8 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -115,7 +115,6 @@ function block_menu() {
   $items['admin/structure/block/manage/%block/configure'] = array(
     'title' => 'Configure block',
     'type' => MENU_DEFAULT_LOCAL_TASK,
-    'context' => MENU_CONTEXT_NONE,
   );
   $items['admin/structure/block/add/%/%'] = array(
     'title' => 'Place block',
@@ -124,6 +123,7 @@ function block_menu() {
   );
   // Block administration is tied to the theme and plugin definition so
   // that the plugin can appropriately attach to this URL structure.
+  // that the plugin can appropriately attach to this URL structure.
   // @todo D8: Use dynamic % arguments instead of static, hard-coded theme names
   //   and plugin IDs to decouple the routes from these dependencies and allow
   //   hook_menu_local_tasks() to check for the untranslated tab_parent path.
diff --git a/core/modules/block/custom_block/custom_block.module b/core/modules/block/custom_block/custom_block.module
index e882e97..fe6a3ce 100644
--- a/core/modules/block/custom_block/custom_block.module
+++ b/core/modules/block/custom_block/custom_block.module
@@ -121,6 +121,7 @@ function custom_block_menu() {
     'title' => 'Delete',
     'weight' => 1,
     'type' => MENU_LOCAL_TASK,
+    'route_name' => 'custom_block.delete',
   );
   return $items;
 }
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index 3829291..cee06c3 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -259,11 +259,11 @@ function contextual_pre_render_links($element) {
 
   $contextual_links_manager = \Drupal::service('plugin.manager.menu.contextual_link');
   foreach ($element['#contextual_links'] as $module => $args) {
-    $result = $contextual_links_manager->getContextualLinksArrayByGroup($args[0], $args[1]);
-    if (!empty($result)) {
+    $contextual_links = $contextual_links_manager->getContextualLinksArrayByGroup($args[0], $args[1]);
+    if (!empty($contextual_links)) {
       unset($element['#contextual_links'][$module]);
     }
-    $items += $result;
+    $items += $contextual_links;
   }
 
   // @todo Remove once all contextual links are converted.
@@ -319,9 +319,9 @@ function contextual_contextual_links_view_alter(&$element, $items) {
  *  - menu:menu:menu=tools:|block:block:block=bartik.tools:
  *
  * So, expressed in a pattern:
- *  <module name>:<parent path>:<path args>:<options>
+ *  <module name>:<group>:<route parameters>:<options>
  *
- * The path args and options are encoded as query strings.
+ * The route parameters and options are encoded as query strings.
  *
  * @param array $contextual_links
  *   The $element['#contextual_links'] value for some render element.
@@ -333,10 +333,10 @@ function contextual_contextual_links_view_alter(&$element, $items) {
 function _contextual_links_to_id($contextual_links) {
   $ids = array();
   foreach ($contextual_links as $module => $args) {
-    $parent_path = $args[0];
-    $path_args = drupal_http_build_query($args[1]);
-    $metadata = drupal_http_build_query((isset($args[2])) ? $args[2] : array());
-    $ids[] = "{$module}:{$parent_path}:{$path_args}:{$metadata}";
+    $group = $args[0];
+    $route_parameters = drupal_http_build_query($args[1]);
+    $options = drupal_http_build_query((isset($args[2])) ? $args[2] : array());
+    $ids[] = "{$module}:{$group}:{$route_parameters}:{$options}";
   }
   return implode('|', $ids);
 }