diff -u b/core/modules/content_translation/content_translation.module b/core/modules/content_translation/content_translation.module
--- b/core/modules/content_translation/content_translation.module
+++ b/core/modules/content_translation/content_translation.module
@@ -53,7 +53,7 @@
  */
 function content_translation_module_implements_alter(&$implementations, $hook) {
   switch ($hook) {
-    // Move our entity_type_alter hook implementation to the end of the list.
+    // Move our hook_entity_type_alter() implementation to the end of the list.
     case 'entity_type_alter':
       $group = $implementations['content_translation'];
       unset($implementations['content_translation']);
diff -u b/core/modules/content_translation/src/Tests/ContentTranslationUITestBase.php b/core/modules/content_translation/src/Tests/ContentTranslationUITestBase.php
--- b/core/modules/content_translation/src/Tests/ContentTranslationUITestBase.php
+++ b/core/modules/content_translation/src/Tests/ContentTranslationUITestBase.php
@@ -218,7 +218,7 @@
       if ($entity->hasTranslation($langcode)) {
         $language = new Language(array('id' => $langcode));
         $view_url = $entity->url('canonical', ['language' => $language]);
-        $elements = $this->xpath('//table//a[@href=:href]', array(':href' => $view_url));
+        $elements = $this->xpath('//table//a[@href=:href]', [':href' => $view_url]);
         $this->assertEqual((string) $elements[0], $entity->getTranslation($langcode)->label(), format_string('Label correctly shown for %language translation.', array('%language' => $langcode)));
         $edit_path = $entity->url('edit-form', array('language' => $language));
         $elements = $this->xpath('//table//ul[@class="dropbutton"]/li/a[@href=:href]', array(':href' => $edit_path));
diff -u b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
--- b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
+++ b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\language\Plugin\LanguageNegotiation;
 
-
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\PathProcessor\OutboundPathProcessorInterface;
@@ -140,6 +139,7 @@
       if (!isset($options['query'][static::QUERY_PARAMETER])) {
         $query_addon = [static::QUERY_PARAMETER => $langcode];
         $options['query'] += $query_addon;
+        // @todo Remove this once https://www.drupal.org/node/2507005 lands.
         $path .= (strpos($path, '?') !== FALSE ? '&' : '?') . UrlHelper::buildQuery($query_addon);
       }
 
@@ -184,6 +184,7 @@
    * than the url language negotiator.
    *
    * @return bool
+   *   TRUE if the configuration condition is met, FALSE otherwise.
    */
   protected function meetsConfigurationCondition() {
     if (!isset($this->meetsConfigurationCondition)) {
@@ -196,7 +197,7 @@
       $check_interface_method = FALSE;
       if (isset($enabled_methods_content[LanguageNegotiationUI::METHOD_ID])) {
         $enabled_methods_interface = $this->config->get('language.types')->get('negotiation.language_interface.enabled') ? : [];
-        $check_interface_method = isset($enabled_methods_interface[LanguageNegotiationUrl::METHOD_ID]) ? TRUE : FALSE;
+        $check_interface_method = isset($enabled_methods_interface[LanguageNegotiationUrl::METHOD_ID]);
       }
       if ($check_interface_method) {
         $check_against_weight = $enabled_methods_content[LanguageNegotiationUI::METHOD_ID];
@@ -224,14 +225,15 @@
    *   The HttpRequest object representing the current request.
    *
    * @return bool
+   *   TRUE if the content entity route condition is met, FALSE otherwise.
    */
   protected function meetsContentEntityRoutesCondition($outbound_route_name, Request $request) {
-    $storage = $this->paths->offsetExists($request) ? $this->paths->offsetGet($request) : [];
+    $storage = isset($this->paths[$request]) ? $this->paths[$request] : [];
     if (!isset($storage[$outbound_route_name])) {
       $content_entity_path_for_current_route = $this->getContentEntityPathForCurrentRequest($request);
       $meets_condition = $content_entity_path_for_current_route ? $this->meetsOutboundRouteToCurrentContentEntityCondition($outbound_route_name, $request) : FALSE;
       $storage[$outbound_route_name] = $meets_condition;
-      $this->paths->offsetSet($request, $storage);
+      $this->paths[$request] = $storage;
     }
 
     return $storage[$outbound_route_name];
@@ -244,6 +246,7 @@
    *   The HttpRequest object representing the current request.
    *
    * @return string
+   *   The path pattern for the content entity from the request.
    */
   protected function getContentEntityPathForCurrentRequest(Request $request) {
     $content_entity_path_for_current_route = '';
@@ -266,11 +269,13 @@
    *   The HttpRequest object representing the current request.
    *
    * @return bool
+   *   TRUE if the outbound route points to the entity on the current route,
+   *   FALSE otherwise.
    */
   protected function meetsOutboundRouteToCurrentContentEntityCondition($outbound_route_name, Request $request) {
     if ($content_entity_path_for_current_route = $this->getContentEntityPathForCurrentRequest($request)) {
       $outbound_route_path = $this->routeProvider->getRouteByName($outbound_route_name)->getPath();
-      if (!empty($this->getContentEntityPaths()[$outbound_route_path])) {
+      if (!empty($this->getContentEntityPaths()[$outbound_route_path]) && $content_entity_path_for_current_route == $this->getContentEntityPaths()[$outbound_route_path]) {
         return TRUE;
       }
     }