core/includes/theme.inc                            |   22 ++++----------
 .../Drupal/language/Plugin/Block/LanguageBlock.php |    1 +
 .../language/Tests/LanguageSwitchingTest.php       |   32 ++++++++++----------
 3 files changed, 23 insertions(+), 32 deletions(-)

diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index f7b00bf..816016d 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1304,8 +1304,8 @@ function theme_links($variables) {
               // Add a "data-drupal-link-query" attribute to let the
               // drupal.active-link library know the query in a standardized
               // manner.
-              if (!empty($link['#options']['query'])) {
-                $query = $link['#options']['query'];
+              if (!empty($link['query'])) {
+                $query = $link['query'];
                 ksort($query);
                 $li_attributes['data-drupal-link-query'] = Json::encode($query);
               }
@@ -1330,23 +1330,13 @@ function theme_links($variables) {
             }
           }
           elseif (isset($link['href'])) {
-            if (!isset($link['#options'])) {
-              $link['#options'] = array();
-            }
-            if (!isset($link['#options']['language'])) {
-              $link['#options']['language'] = NULL;
-            }
-            if (!isset($link['#options']['query'])) {
-              $link['#options']['query'] = array();
-            }
-
             // @see l()
             if (\Drupal::currentUser()->isAuthenticated()) {
               // Add a "data-drupal-link-query" attribute to let the
               // drupal.active-link library know the query in a standardized
               // manner.
-              if (!empty($link['#options']['query'])) {
-                $query = $link['#options']['query'];
+              if (!empty($link['query'])) {
+                $query = $link['query'];
                 ksort($query);
                 $li_attributes['data-drupal-link-query'] = Json::encode($query);
               }
@@ -1380,9 +1370,9 @@ function theme_links($variables) {
               // An active link's path is equal to the current path.
               $url_is_active = ($link['href'] == $active['path'] || ($link['href'] == '<front>' && $active['front_page']))
               // The language of an active link is equal to the current language.
-              && (empty($link['#options']['language']) || $link['#options']['language']->id == $active['language'])
+              && (empty($link['language']) || $link['language']->id == $active['language'])
               // The query parameters of an active link are equal to the current parameters.
-              && ($link['#options']['query'] == $active['query']);
+              && (empty($link['query']) || $link['query'] == $active['query']);
 
               // Add the "active" class if appropriate.
               if ($url_is_active) {
diff --git a/core/modules/language/lib/Drupal/language/Plugin/Block/LanguageBlock.php b/core/modules/language/lib/Drupal/language/Plugin/Block/LanguageBlock.php
index fae6081..e347de5 100644
--- a/core/modules/language/lib/Drupal/language/Plugin/Block/LanguageBlock.php
+++ b/core/modules/language/lib/Drupal/language/Plugin/Block/LanguageBlock.php
@@ -49,6 +49,7 @@ public function build() {
             "language-switcher-{$links->method_id}",
           ),
         ),
+        '#set_active_class' => TRUE,
       );
     }
     return $build;
diff --git a/core/modules/language/lib/Drupal/language/Tests/LanguageSwitchingTest.php b/core/modules/language/lib/Drupal/language/Tests/LanguageSwitchingTest.php
index e1ebfc0..826fcf9 100644
--- a/core/modules/language/lib/Drupal/language/Tests/LanguageSwitchingTest.php
+++ b/core/modules/language/lib/Drupal/language/Tests/LanguageSwitchingTest.php
@@ -72,28 +72,28 @@ protected function doTestLanguageBlockAuthenticated($block_label) {
     $this->drupalGet('');
     $this->assertText($block_label, 'Language switcher block found.');
 
-    // Assert that only the current language is marked as active.
+    // Assert that each list item and anchor element has the appropriate data-
+    // attributes.
     list($language_switcher) = $this->xpath('//div[@id=:id]/div[contains(@class, "content")]', array(':id' => 'block-test-language-block'));
-    $links = array(
-      'active' => array(),
-      'inactive' => array(),
-    );
+    $list_items = array();
     $anchors = array();
-    foreach ($language_switcher->ul->li as $link) {
-      $classes = explode(" ", (string) $link['class']);
+    foreach ($language_switcher->ul->li as $list_item) {
+      $classes = explode(" ", (string) $list_item['class']);
       list($langcode) = array_intersect($classes, array('en', 'fr'));
-      if (in_array('active', $classes)) {
-        $links['active'][] = $langcode;
-      }
-      else {
-        $links['inactive'][] = $langcode;
-      }
+      $list_items[] = array(
+        'langcode_class' => $langcode,
+        'data-drupal-link-system-path' => (string) $list_item['data-drupal-link-system-path'],
+      );
       $anchors[] = array(
-        'hreflang' => (string) $link->a['hreflang'],
-        'data-drupal-link-system-path' => (string) $link->a['data-drupal-link-system-path'],
+        'hreflang' => (string) $list_item->a['hreflang'],
+        'data-drupal-link-system-path' => (string) $list_item->a['data-drupal-link-system-path'],
       );
     }
-    $this->assertIdentical($links, array('active' => array('en'), 'inactive' => array('fr')), 'Only the current language list item is marked as active on the language switcher block.');
+    $expected_list_items = array(
+      0 => array('langcode_class' => 'en', 'data-drupal-link-system-path' => 'user/2'),
+      1 => array('langcode_class' => 'fr', 'data-drupal-link-system-path' => 'user/2'),
+    );
+    $this->assertIdentical($list_items, $expected_list_items, 'The list items have the correct attributes that will allow the drupal.active-link library to mark them as active.');
     $expected_anchors = array(
       0 => array('hreflang' => 'en', 'data-drupal-link-system-path' => 'user/2'),
       1 => array('hreflang' => 'fr', 'data-drupal-link-system-path' => 'user/2'),