diff --git a/core/modules/menu/lib/Drupal/menu/Tests/MenuLanguageTest.php b/core/modules/menu/lib/Drupal/menu/Tests/MenuLanguageTest.php
index 408ca36..a2ce4a2 100644
--- a/core/modules/menu/lib/Drupal/menu/Tests/MenuLanguageTest.php
+++ b/core/modules/menu/lib/Drupal/menu/Tests/MenuLanguageTest.php
@@ -88,7 +88,7 @@ function testMenuLanguage() {
     // Check the link was added with the correct menu link default language.
     $menu_links = entity_load_multiple_by_properties('menu_link', array('link_title' => $title));
     $menu_link = reset($menu_links);
-    $this->assertTrue('Menu link was found in database.');
+    $this->assertTrue($menu_link, 'Menu link was found in database.');
     $this->assertMenuLink($menu_link->id(), array('menu_name' => $menu_name, 'link_path' => $sample_link_path, 'langcode' => 'bb'));
 
     // Edit menu link default, changing it to cc.
@@ -110,7 +110,7 @@ function testMenuLanguage() {
     // Check the link was added with the correct new menu link default language.
     $menu_links = entity_load_multiple_by_properties('menu_link', array('link_title' => $title));
     $menu_link = reset($menu_links);
-    $this->assertTrue('Menu link was found in database.');
+    $this->assertTrue($menu_link, 'Menu link was found in database.');
     $this->assertMenuLink($menu_link->id(), array('menu_name' => $menu_name, 'link_path' => $sample_link_path, 'langcode' => 'cc'));
 
     // Edit menu to hide the language select on menu link item add.
@@ -152,7 +152,7 @@ function assertMenuLink($mlid, array $expected_item) {
     $item = entity_load('menu_link', $mlid);
     $options = $item->options;
     if (!empty($options['query'])) {
-      $item['link_path'] .= '?' . drupal_http_build_query($options['query']);
+      $item['link_path'] .= '?' . \Drupal::urlGenerator()->httpBuildQuery($options['query']);
     }
     if (!empty($options['fragment'])) {
       $item['link_path'] .= '#' . $options['fragment'];
diff --git a/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php b/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
index a5c5456..16c07c8 100644
--- a/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
+++ b/core/modules/menu/lib/Drupal/menu/Tests/MenuTest.php
@@ -158,7 +158,6 @@ function addCustomMenu() {
     $this->assertText($label, 'Menu created');
 
     // Enable the custom menu block.
-    $menu_name = 'menu-' . $menu_name; // Drupal prepends the name with 'menu-'.
     // Confirm that the custom menu block is available.
     $this->drupalGet('admin/structure/block/list/block_plugin_ui:' . config('system.theme')->get('default') . '/add');
     $this->assertText($label);
@@ -390,7 +389,7 @@ function addMenuLink($plid = 0, $link = '<front>', $menu_name = 'tools', $expand
 
     $menu_links = entity_load_multiple_by_properties('menu_link', array('link_title' => $title));
     $menu_link = reset($menu_links);
-    $this->assertTrue('Menu link was found in database.');
+    $this->assertTrue($menu_link, 'Menu link was found in database.');
     $this->assertMenuLink($menu_link->id(), array('menu_name' => $menu_name, 'link_path' => $link, 'has_children' => 0, 'plid' => $plid));
 
     return $menu_link;
@@ -586,7 +585,7 @@ function assertMenuLink($mlid, array $expected_item) {
     $item = entity_load('menu_link', $mlid);
     $options = $item->options;
     if (!empty($options['query'])) {
-      $item['link_path'] .= '?' . drupal_http_build_query($options['query']);
+      $item['link_path'] .= '?' . \Drupal::urlGenerator()->httpBuildQuery($options['query']);
     }
     if (!empty($options['fragment'])) {
       $item['link_path'] .= '#' . $options['fragment'];
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
index 974ea30..9946e79 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkFormController.php
@@ -86,7 +86,7 @@ public function form(array $form, array &$form_state) {
     // $base_path.
     $path = $menu_link->link_path;
     if (isset($menu_link->options['query'])) {
-      $path .= '?' . drupal_http_build_query($menu_link->options['query']);
+      $path .= '?' . \Drupal::urlGenerator()->httpBuildQuery($menu_link->options['query']);
     }
     if (isset($menu_link->options['fragment'])) {
       $path .= '#' . $menu_link->options['fragment'];
@@ -165,7 +165,13 @@ public function form(array $form, array &$form_state) {
     if ($menu_link->isNew()) {
       // Adding a new menu link, use the default from language settings config.
       // If no default for menu links, default to the language of the menu.
-      $default_langcode = (!is_null($language_configuration['langcode']) ? $language_configuration['langcode'] : $menu->langcode);
+      if (!is_null($language_configuration['langcode'])) {
+        $default_langcode = $language_configuration['langcode'];
+      }
+      else {
+        $menu = menu_load($menu_link->menu_name);
+        $default_langcode = $menu->langcode;
+      }
     }
     else {
       // Editing an already existing menu link, so use it's saved language.