diff --git a/core/includes/common.inc b/core/includes/common.inc
index 9f3f373..54c77c7 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -3796,13 +3796,13 @@ function drupal_js_defaults($data = NULL) {
  * is to add another element to the $javascript array, deriving from
  * drupal_js_defaults(). See locale_js_alter() for an example of this.
  *
- * @param $scope
+ * @param string $scope
  *   (optional) The scope for which the JavaScript rules should be returned.
  *   Defaults to 'header'.
- * @param $javascript
+ * @param array $javascript
  *   (optional) An array with all JavaScript code. Defaults to the default
  *   JavaScript array for the given scope.
- * @param $skip_alter
+ * @param bool $skip_alter
  *   (optional) If set to TRUE, this function skips calling drupal_alter() on
  *   $javascript, useful when the calling function passes a $javascript array
  *   that has already been altered.
@@ -3845,7 +3845,6 @@ function drupal_get_js($scope = 'header', $javascript = NULL, $skip_alter = FALS
       // a later AJAX request can be rendered using the same theme.
       // @see ajax_base_page_theme()
       $setting['ajaxPageState']['theme'] = $theme_key;
-      error_log('js ahoy');
       // Checks that the DB is available before filling theme_token.
       if (!defined('MAINTENANCE_MODE')) {
         $setting['ajaxPageState']['theme_token'] = drupal_get_token($theme_key);
diff --git a/core/lib/Drupal/Core/Ajax/AjaxResponse.php b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
index ccd7ce3..2d3cbe1 100644
--- a/core/lib/Drupal/Core/Ajax/AjaxResponse.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
@@ -27,7 +27,7 @@ class AjaxResponse extends JsonResponse {
    *
    * @param object $command
    *   An AJAX command object implementing CommandInterface.
-   * @param boolean $prepend
+   * @param bool $prepend
    *   A boolean which determines whether the new command should be executed
    *   before previously added commands. Defaults to FALSE.
    *
@@ -111,9 +111,6 @@ protected function ajaxRender(Request $request) {
       unset($items['js']['settings']);
     }
 
-    // Make sure that drupal_get_js() returns settings by injecting an empty
-    // setting.
-    $items['js']['settings'] = array('data' => array(), 'scope' => 'header');
     $styles = drupal_get_css($items['css'], TRUE);
     $scripts_footer = drupal_get_js('footer', $items['js'], TRUE);
     $scripts_header = drupal_get_js('header', $items['js'], TRUE);
@@ -137,6 +134,36 @@ protected function ajaxRender(Request $request) {
     $scripts = drupal_add_js();
     if (!empty($scripts['settings'])) {
       $settings = drupal_merge_js_settings($scripts['settings']['data']);
+      // Setup ajaxPageState.
+      global $theme_key;
+      // Provide the page with information about the theme that's used, so that
+      // a later AJAX request can be rendered using the same theme.
+      // @see ajax_base_page_theme()
+      $settings['ajaxPageState']['theme'] = $theme_key;
+      // Checks that the DB is available before filling theme_token.
+      if (!defined('MAINTENANCE_MODE')) {
+        $settings['ajaxPageState']['theme_token'] = drupal_get_token($theme_key);
+      }
+
+      // Provide the page with information about the individual JavaScript files
+      // used, information not otherwise available when aggregation is enabled.
+      $settings['ajaxPageState']['js'] = array_fill_keys(array_keys($scripts), 1);
+      unset($settings['ajaxPageState']['js']['settings']);
+
+      // Provide the page with information about the individual CSS files used,
+      // information not otherwise available when CSS aggregation is enabled.
+      // The setting is attached later in this function, but is set here, so
+      // that CSS files removed in drupal_process_attached() are still
+      // considered "used" and prevented from being added in a later AJAX
+      // request.
+      // Skip if no files were added to the page otherwise jQuery.extend() will
+      // overwrite the Drupal.settings.ajaxPageState.css object with an empty
+      // array.
+      $css = drupal_add_css();
+      if (!empty($css)) {
+        // Cast the array to an object to be on the safe side even if not empty.
+        $settings['ajaxPageState']['css'] = (object) array_fill_keys(array_keys($css), 1);
+      }
       $this->addCommand(new SettingsCommand($settings, TRUE), TRUE);
     }
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php b/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
index 32aea71..29c8bfb 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
@@ -35,7 +35,7 @@ function testDialog() {
       'settings' => NULL,
       'data' => $dialog_contents,
       'dialogOptions' => array(
-        'modal' => true,
+        'modal' => TRUE,
         'title' => 'AJAX Dialog',
       ),
     );
@@ -45,7 +45,7 @@ function testDialog() {
       'settings' => NULL,
       'data' => $dialog_contents,
       'dialogOptions' => array(
-        'modal' => false,
+        'modal' => FALSE,
         'title' => 'AJAX Dialog',
       ),
     );
diff --git a/core/modules/system/lib/Drupal/system/Tests/Ajax/FrameworkTest.php b/core/modules/system/lib/Drupal/system/Tests/Ajax/FrameworkTest.php
index 219bb44..1ec42e5 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Ajax/FrameworkTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Ajax/FrameworkTest.php
@@ -52,6 +52,7 @@ function testOrder() {
     $expected_commands[1] = new AddCssCommand(drupal_get_css(drupal_add_css(), TRUE));
     drupal_static_reset('drupal_add_js');
     drupal_add_js($path . '/system.js');
+
     $expected_commands[2] = new PrependCommand('head', drupal_get_js('header', drupal_add_js(), TRUE));
     drupal_static_reset('drupal_add_js');
     drupal_add_js($path . '/system.modules.js', array('scope' => 'footer'));