.../lib/Drupal/ckeditor/CKEditorPluginManager.php  |    2 +-
 .../ckeditor/Plugin/editor/editor/CKEditor.php     |   11 +++---
 .../Drupal/ckeditor/Tests/CKEditorAdminTest.php    |   28 ++++++-------
 core/modules/editor/editor.module                  |   41 +++++++++++---------
 .../lib/Drupal/editor/Plugin/EditorInterface.php   |    4 +-
 .../lib/Drupal/editor/Tests/EditorAdminTest.php    |   26 ++++++-------
 6 files changed, 58 insertions(+), 54 deletions(-)

diff --git a/core/modules/ckeditor/lib/Drupal/ckeditor/CKEditorPluginManager.php b/core/modules/ckeditor/lib/Drupal/ckeditor/CKEditorPluginManager.php
index 4eee1eb..b895fe8 100644
--- a/core/modules/ckeditor/lib/Drupal/ckeditor/CKEditorPluginManager.php
+++ b/core/modules/ckeditor/lib/Drupal/ckeditor/CKEditorPluginManager.php
@@ -132,7 +132,7 @@ public function injectPluginSettingsForm(array &$form, array &$form_state, Edito
         $form['plugins'][$plugin_id] = array(
           '#type' => 'details',
           '#title' => $definitions[$plugin_id]['label'],
-          '#group' => 'editor_settings][plugin_settings',
+          '#group' => 'editor][settings][plugin_settings',
         );
         $form['plugins'][$plugin_id] += $plugin->settingsForm($plugin_settings_form, $form_state, $editor);
       }
diff --git a/core/modules/ckeditor/lib/Drupal/ckeditor/Plugin/editor/editor/CKEditor.php b/core/modules/ckeditor/lib/Drupal/ckeditor/Plugin/editor/editor/CKEditor.php
index c1c3efe..2dffa09 100644
--- a/core/modules/ckeditor/lib/Drupal/ckeditor/Plugin/editor/editor/CKEditor.php
+++ b/core/modules/ckeditor/lib/Drupal/ckeditor/Plugin/editor/editor/CKEditor.php
@@ -50,8 +50,7 @@ function settingsForm(array $form, array &$form_state, Editor $editor) {
     $manager = drupal_container()->get('plugin.manager.ckeditor.plugin');
 
     $form['toolbar'] = array(
-      '#type' => 'details',
-      '#title' => t('Toolbar'),
+      '#type' => 'container',
       '#attached' => array(
         'library' => array(array('ckeditor', 'drupal.ckeditor.admin')),
         'js' => array(
@@ -91,15 +90,15 @@ function settingsForm(array $form, array &$form_state, Editor $editor) {
    */
   function settingsFormSubmit(array $form, array &$form_state) {
     // Modify the toolbar settings by reference. The values in
-    // $form_state['values']['editor_settings'] will be saved directly by
+    // $form_state['values']['editor']['settings'] will be saved directly by
     // editor_form_filter_admin_format_submit().
-    $toolbar_settings = &$form_state['values']['editor_settings']['toolbar'];
+    $toolbar_settings = &$form_state['values']['editor']['settings']['toolbar'];
 
     $toolbar_settings['buttons'] = json_decode($toolbar_settings['buttons'], FALSE);
 
     // Remove the plugin settings' vertical tabs state; no need to save that.
-    if (isset($form_state['values']['editor_settings']['plugins'])) {
-      unset($form_state['values']['editor_settings']['plugin_settings']);
+    if (isset($form_state['values']['editor']['settings']['plugins'])) {
+      unset($form_state['values']['editor']['settings']['plugin_settings']);
     }
   }
 
diff --git a/core/modules/ckeditor/lib/Drupal/ckeditor/Tests/CKEditorAdminTest.php b/core/modules/ckeditor/lib/Drupal/ckeditor/Tests/CKEditorAdminTest.php
index 7f05bc6..72811e9 100644
--- a/core/modules/ckeditor/lib/Drupal/ckeditor/Tests/CKEditorAdminTest.php
+++ b/core/modules/ckeditor/lib/Drupal/ckeditor/Tests/CKEditorAdminTest.php
@@ -58,9 +58,9 @@ function testAdmin() {
     $this->assertFalse($editor, 'No Editor config entity exists yet.');
 
     // Verify the "Text Editor" <select> when a text editor is available.
-    $select = $this->xpath('//select[@name="editor"]');
-    $select_is_disabled = $this->xpath('//select[@name="editor" and @disabled="disabled"]');
-    $options = $this->xpath('//select[@name="editor"]/option');
+    $select = $this->xpath('//select[@name="editor[editor]"]');
+    $select_is_disabled = $this->xpath('//select[@name="editor[editor]" and @disabled="disabled"]');
+    $options = $this->xpath('//select[@name="editor[editor]"]/option');
     $this->assertTrue(count($select) === 1, 'The Text Editor select exists.');
     $this->assertTrue(count($select_is_disabled) === 0, 'The Text Editor select is not disabled.');
     $this->assertTrue(count($options) === 2, 'The Text Editor select has two options.');
@@ -70,7 +70,7 @@ function testAdmin() {
 
     // Select the "CKEditor" editor and click the "Configure" button.
     $edit = array(
-      'editor' => 'ckeditor',
+      'editor[editor]' => 'ckeditor',
     );
     // $this->drupalPost(NULL, $edit, t('Configure'));
     $this->drupalPostAjax(NULL, $edit, 'editor_configure');
@@ -79,9 +79,9 @@ function testAdmin() {
 
     // Default configuration.
     $default_buttons_value = '[["Source","|","Bold","Italic","|","NumberedList","BulletedList","Blockquote","|","JustifyLeft","JustifyCenter","JustifyRight","|","Link","Unlink","|","Image","Maximize"]]';
-    $this->assertFieldByName('editor_settings[toolbar][buttons]', $default_buttons_value, 'Buttons configuration');
-    $ctrl_l_radio = $this->xpath('//input[@type="radio" and @name="editor_settings[plugins][internal][link_shortcut]" and @value="CTRL+L" and @checked="checked"]');
-    $ctrl_k_radio = $this->xpath('//input[@type="radio" and @name="editor_settings[plugins][internal][link_shortcut]" and @value="CTRL+K" and not(@checked)]');
+    $this->assertFieldByName('editor[settings][toolbar][buttons]', $default_buttons_value, 'Buttons configuration');
+    $ctrl_l_radio = $this->xpath('//input[@type="radio" and @name="editor[settings][plugins][internal][link_shortcut]" and @value="CTRL+L" and @checked="checked"]');
+    $ctrl_k_radio = $this->xpath('//input[@type="radio" and @name="editor[settings][plugins][internal][link_shortcut]" and @value="CTRL+K" and not(@checked)]');
     $this->assertTrue(count($ctrl_l_radio) === 1, 'The CTRL+L radio exists and is checked.');
     $this->assertTrue(count($ctrl_k_radio) === 1, 'The CTRL+K radio exists and is not checked.');
     $this->drupalPost(NULL, $edit, t('Save configuration'));
@@ -95,11 +95,11 @@ function testAdmin() {
 
     // Configure a plugin.
     $edit = array(
-      'editor_settings[plugins][internal][link_shortcut]' => 'CTRL+K',
+      'editor[settings][plugins][internal][link_shortcut]' => 'CTRL+K',
     );
     $this->drupalPost(NULL, $edit, t('Save configuration'));
-    $ctrl_l_radio = $this->xpath('//input[@type="radio" and @name="editor_settings[plugins][internal][link_shortcut]" and @value="CTRL+L" and not(@checked)]');
-    $ctrl_k_radio = $this->xpath('//input[@type="radio" and @name="editor_settings[plugins][internal][link_shortcut]" and @value="CTRL+K" and @checked="checked"]');
+    $ctrl_l_radio = $this->xpath('//input[@type="radio" and @name="editor[settings][plugins][internal][link_shortcut]" and @value="CTRL+L" and not(@checked)]');
+    $ctrl_k_radio = $this->xpath('//input[@type="radio" and @name="editor[settings][plugins][internal][link_shortcut]" and @value="CTRL+K" and @checked="checked"]');
     $this->assertTrue(count($ctrl_l_radio) === 1, 'The CTRL+L radio exists and is not checked.');
     $this->assertTrue(count($ctrl_k_radio) === 1, 'The CTRL+K radio exists and is checked.');
     $expected_settings['plugins']['internal']['link_shortcut'] = 'CTRL+K';
@@ -110,7 +110,7 @@ function testAdmin() {
     // "Drag and drop" buttons: remove one button, add a separator, add a button
     // and finally, add a button to a new row.
     $edit = array(
-      'editor_settings[toolbar][buttons]' => '[["Source","|","Bold","Italic","|","NumberedList","BulletedList","Blockquote","|","JustifyLeft","JustifyCenter","JustifyRight","|","Link","Unlink","|","Image","|","Undo"],["Redo"]]'
+      'editor[settings][toolbar][buttons]' => '[["Source","|","Bold","Italic","|","NumberedList","BulletedList","Blockquote","|","JustifyLeft","JustifyCenter","JustifyRight","|","Link","Unlink","|","Image","|","Undo"],["Redo"]]'
     );
     $this->drupalPost(NULL, $edit, t('Save configuration'));
     $expected_settings['toolbar']['buttons'][0][17] = '|';
@@ -125,7 +125,7 @@ function testAdmin() {
     module_enable(array('ckeditor_test'));
     drupal_container()->get('plugin.manager.ckeditor.plugin')->clearCachedDefinitions();
     $this->drupalGet('admin/config/content/formats/filtered_html');
-    $ultra_llama_mode_checkbox = $this->xpath('//input[@type="checkbox" and @name="editor_settings[plugins][llama_contextual_and_button][ultra_llama_mode]" and not(@checked)]');
+    $ultra_llama_mode_checkbox = $this->xpath('//input[@type="checkbox" and @name="editor[settings][plugins][llama_contextual_and_button][ultra_llama_mode]" and not(@checked)]');
     $this->assertTrue(count($ultra_llama_mode_checkbox) === 1, 'The "Ultra llama mode" checkbox exists and is not checked.');
     $editor = entity_load('editor', 'filtered_html');
     $this->assertTrue($editor instanceof Editor, 'An Editor config entity exists.');
@@ -133,10 +133,10 @@ function testAdmin() {
 
     // Finally, check the "Ultra llama mode" checkbox.
     $edit = array(
-      'editor_settings[plugins][llama_contextual_and_button][ultra_llama_mode]' => '1',
+      'editor[settings][plugins][llama_contextual_and_button][ultra_llama_mode]' => '1',
     );
     $this->drupalPost(NULL, $edit, t('Save configuration'));
-    $ultra_llama_mode_checkbox = $this->xpath('//input[@type="checkbox" and @name="editor_settings[plugins][llama_contextual_and_button][ultra_llama_mode]" and @checked="checked"]');
+    $ultra_llama_mode_checkbox = $this->xpath('//input[@type="checkbox" and @name="editor[settings][plugins][llama_contextual_and_button][ultra_llama_mode]" and @checked="checked"]');
     $this->assertTrue(count($ultra_llama_mode_checkbox) === 1, 'The "Ultra llama mode" checkbox exists and is checked.');
     $expected_settings['plugins']['llama_contextual_and_button']['ultra_llama_mode'] = '1';
     $editor = entity_load('editor', 'filtered_html');
diff --git a/core/modules/editor/editor.module b/core/modules/editor/editor.module
index a40c249..89fd11b 100644
--- a/core/modules/editor/editor.module
+++ b/core/modules/editor/editor.module
@@ -119,21 +119,26 @@ function editor_form_filter_admin_format_form_alter(&$form, &$form_state) {
   // Associate a text editor with this text format.
   $editor_options = $manager->listOptions();
   $form['editor'] = array(
-    '#type' => 'select',
+    '#type' => 'fieldset',
     '#title' => t('Text editor'),
-    '#options' => $editor_options,
-    '#empty_option' => t('None'),
-    '#default_value' => $editor ? $editor->editor : '',
     // Position the editor selection before the filter settings (weight of 0),
     // but after the filter label and name (weight of -20).
     '#weight' => -9,
+  );
+  $form['editor']['editor'] = array(
+    '#type' => 'select',
+    '#title' => t('Current text editor'),
+    '#options' => $editor_options,
+    '#empty_option' => t('None'),
+    '#default_value' => $editor ? $editor->editor : '',
     '#ajax' => array(
       'trigger_as' => array('name' => 'editor_configure'),
       'callback' => 'editor_form_filter_admin_form_ajax',
       'wrapper' => 'editor-settings-wrapper',
     ),
+    '#weight' => -10,
   );
-  $form['editor_configure'] = array(
+  $form['editor']['configure'] = array(
     '#type' => 'submit',
     '#name' => 'editor_configure',
     '#value' => t('Configure'),
@@ -143,17 +148,17 @@ function editor_form_filter_admin_format_form_alter(&$form, &$form_state) {
       'callback' => 'editor_form_filter_admin_form_ajax',
       'wrapper' => 'editor-settings-wrapper',
     ),
-    '#weight' => -9,
+    '#weight' => -10,
     '#attributes' => array('class' => array('js-hide')),
   );
 
   // If there aren't any options (other than "None"), disable the select list.
   if (empty($editor_options)) {
-    $form['editor']['#disabled'] = TRUE;
-    $form['editor']['#description'] = t('This option is disabled because no modules that provide a text editor are currently enabled.');
+    $form['editor']['editor']['#disabled'] = TRUE;
+    $form['editor']['editor']['#description'] = t('This option is disabled because no modules that provide a text editor are currently enabled.');
   }
 
-  $form['editor_settings'] = array(
+  $form['editor']['settings'] = array(
     '#tree' => TRUE,
     '#weight' => -8,
     '#type' => 'container',
@@ -165,8 +170,8 @@ function editor_form_filter_admin_format_form_alter(&$form, &$form_state) {
     $plugin = $manager->createInstance($editor->editor);
     $settings_form = array();
     $settings_form['#element_validate'][] = array($plugin, 'settingsFormValidate');
-    $form['editor_settings']['settings'] = $plugin->settingsForm($settings_form, $form_state, $editor);
-    $form['editor_settings']['settings']['#parents'] = array('editor_settings');
+    $form['editor']['settings']['subform'] = $plugin->settingsForm($settings_form, $form_state, $editor);
+    $form['editor']['settings']['subform']['#parents'] = array('editor', 'settings');
     $form['#submit'][] = array($plugin, 'settingsFormSubmit');
   }
 
@@ -178,14 +183,14 @@ function editor_form_filter_admin_format_form_alter(&$form, &$form_state) {
  */
 function editor_form_filter_admin_format_editor_configure($form, &$form_state) {
   $editor = $form_state['editor'];
-  if (isset($form_state['values']['editor'])) {
-    if ($form_state['values']['editor'] === '') {
+  if (isset($form_state['values']['editor']['editor'])) {
+    if ($form_state['values']['editor']['editor'] === '') {
       $form_state['editor'] = FALSE;
     }
-    elseif (empty($editor) || $form_state['values']['editor'] !== $editor->editor) {
+    elseif (empty($editor) || $form_state['values']['editor']['editor'] !== $editor->editor) {
       $editor = entity_create('editor', array(
         'format' => $form['#format']->format,
-        'editor' => $form_state['values']['editor'],
+        'editor' => $form_state['values']['editor']['editor'],
       ));
       $form_state['editor'] = $editor;
     }
@@ -197,7 +202,7 @@ function editor_form_filter_admin_format_editor_configure($form, &$form_state) {
  * AJAX callback handler for filter_admin_format_form().
  */
 function editor_form_filter_admin_form_ajax($form, &$form_state) {
-  return $form['editor_settings'];
+  return $form['editor']['settings'];
 }
 
 /**
@@ -212,8 +217,8 @@ function editor_form_filter_admin_format_submit($form, &$form_state) {
   }
 
   // Create a new editor or update the existing editor.
-  if ($form_state['values']['editor'] !== '') {
-    $form_state['editor']->settings = $form_state['values']['editor_settings'];
+  if ($form_state['values']['editor']['editor'] !== '') {
+    $form_state['editor']->settings = $form_state['values']['editor']['settings'];
     $form_state['editor']->save();
   }
 }
diff --git a/core/modules/editor/lib/Drupal/editor/Plugin/EditorInterface.php b/core/modules/editor/lib/Drupal/editor/Plugin/EditorInterface.php
index 1fcbec3..939d877 100644
--- a/core/modules/editor/lib/Drupal/editor/Plugin/EditorInterface.php
+++ b/core/modules/editor/lib/Drupal/editor/Plugin/EditorInterface.php
@@ -52,7 +52,7 @@ function settingsForm(array $form, array &$form_state, Editor $editor);
    * Validates the settings form for an editor.
    *
    * The contents of the editor settings are located in
-   * $form_state['values']['editor_settings']. Calls to form_error() should
+   * $form_state['values']['editor']['settings']. Calls to form_error() should
    * reflect this location in the settings form.
    *
    * @param array $form
@@ -65,7 +65,7 @@ function settingsFormValidate(array $form, array &$form_state);
   /**
    * Modifies any values in the form state to prepare them for saving.
    *
-   * Values in $form_state['values']['editor_settings'] are saved by Editor
+   * Values in $form_state['values']['editor']['settings'] are saved by Editor
    * module in editor_form_filter_admin_format_submit().
    *
    * @param array $form
diff --git a/core/modules/editor/lib/Drupal/editor/Tests/EditorAdminTest.php b/core/modules/editor/lib/Drupal/editor/Tests/EditorAdminTest.php
index f3b834a..783fdd9 100644
--- a/core/modules/editor/lib/Drupal/editor/Tests/EditorAdminTest.php
+++ b/core/modules/editor/lib/Drupal/editor/Tests/EditorAdminTest.php
@@ -56,9 +56,9 @@ function testWithoutEditorAvailable() {
     $this->assertTrue($roles_pos < $editor_pos && $editor_pos < $filters_pos, '"Text Editor" select appears in the correct location of the text format configuration UI.');
 
     // Verify the <select>.
-    $select = $this->xpath('//select[@name="editor"]');
-    $select_is_disabled = $this->xpath('//select[@name="editor" and @disabled="disabled"]');
-    $options = $this->xpath('//select[@name="editor"]/option');
+    $select = $this->xpath('//select[@name="editor[editor]"]');
+    $select_is_disabled = $this->xpath('//select[@name="editor[editor]" and @disabled="disabled"]');
+    $options = $this->xpath('//select[@name="editor[editor]"]/option');
     $this->assertTrue(count($select) === 1, 'The Text Editor select exists.');
     $this->assertTrue(count($select_is_disabled) === 1, 'The Text Editor select is disabled.');
     $this->assertTrue(count($options) === 1, 'The Text Editor select has only one option.');
@@ -72,9 +72,9 @@ function testWithoutEditorAvailable() {
     $this->drupalGet('admin/config/content/formats/filtered_html');
 
     // Verify the <select> when a text editor is available.
-    $select = $this->xpath('//select[@name="editor"]');
-    $select_is_disabled = $this->xpath('//select[@name="editor" and @disabled="disabled"]');
-    $options = $this->xpath('//select[@name="editor"]/option');
+    $select = $this->xpath('//select[@name="editor[editor]"]');
+    $select_is_disabled = $this->xpath('//select[@name="editor[editor]" and @disabled="disabled"]');
+    $options = $this->xpath('//select[@name="editor[editor]"]/option');
     $this->assertTrue(count($select) === 1, 'The Text Editor select exists.');
     $this->assertTrue(count($select_is_disabled) === 0, 'The Text Editor select is not disabled.');
     $this->assertTrue(count($options) === 2, 'The Text Editor select has two options.');
@@ -86,15 +86,15 @@ function testWithoutEditorAvailable() {
 
     // Select the "Unicorn Editor" editor and click the "Configure" button.
     $edit = array(
-      'editor' => 'unicorn',
+      'editor[editor]' => 'unicorn',
     );
     $this->drupalPostAjax(NULL, $edit, 'editor_configure');
-    $unicorn_setting_foo = $this->xpath('//input[@name="editor_settings[foo]" and @type="text" and @value="bar"]');
+    $unicorn_setting_foo = $this->xpath('//input[@name="editor[settings][foo]" and @type="text" and @value="bar"]');
     $this->assertTrue(count($unicorn_setting_foo), "Unicorn Editor's settings form is present.");
-    $options = $this->xpath('//select[@name="editor"]/option');
+    $options = $this->xpath('//select[@name="editor[editor]"]/option');
 
     // Now configure the setting to another value.
-    $edit['editor_settings[foo]'] = 'baz';
+    $edit['editor[settings][foo]'] = 'baz';
     $this->drupalPost(NULL, $edit, t('Save configuration'));
 
     // Verify the editor configuration is saved correctly.
@@ -105,9 +105,9 @@ function testWithoutEditorAvailable() {
     $this->assertIdentical($editor->settings['rainbows'], true, 'The text editor defaults added by hook_editor_settings_defaults() are retrieved correctly.');
     $this->assertIdentical($editor->settings['sparkles'], false, 'The text editor defaults modified by hook_editor_settings_defaults_alter() are retrieved correctly.');
     $this->drupalGet('admin/config/content/formats/filtered_html');
-    $select = $this->xpath('//select[@name="editor"]');
-    $select_is_disabled = $this->xpath('//select[@name="editor" and @disabled="disabled"]');
-    $options = $this->xpath('//select[@name="editor"]/option');
+    $select = $this->xpath('//select[@name="editor[editor]"]');
+    $select_is_disabled = $this->xpath('//select[@name="editor[editor]" and @disabled="disabled"]');
+    $options = $this->xpath('//select[@name="editor[editor]"]/option');
     $this->assertTrue(count($select) === 1, 'The Text Editor select exists.');
     $this->assertTrue(count($select_is_disabled) === 0, 'The Text Editor select is not disabled.');
     $this->assertTrue(count($options) === 2, 'The Text Editor select has two options.');