commit 92f67b7e163357e5f70b0276505237fe2553e841
Author: Joel Pittet <joel@pittet.ca>
Date:   Fri Jan 3 18:42:05 2014 -0800

    cleanup and whitespace

diff --git a/core/includes/form.inc b/core/includes/form.inc
index 1dcf77c..44ed906 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -994,7 +994,7 @@ function theme_fieldset($variables) {
 function template_preprocess_details(&$variables) {
   $element = $variables['element'];
   $variables['attributes'] = $element['#attributes'];
-  $variables['summary_attributes'] = new Attribute(array());
+  $variables['summary_attributes'] = new Attribute();
   if (!empty($element['#title'])) {
     $variables['summary_attributes']['role'] = 'button';
     if (!empty($element['#attributes']['id'])) {
@@ -1961,9 +1961,6 @@ function form_process_group(&$element, &$form_state) {
  */
 function form_pre_render_details($element) {
   element_set_attributes($element, array('id'));
-  if (!isset($element['#attributes']['class'])) {
-    $element['#attributes']['class'] = array();
-  }
 
   // The .form-wrapper class is required for #states to treat details like
   // containers.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
index 12d02b0..a9c0138 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
@@ -598,9 +598,7 @@ function testDrupalRenderChildrenPostRenderCache() {
     $element = array('#cache' => $element['#cache']);
     $cached_element = cache()->get(drupal_render_cid_create($element))->data;
     $expected_element = array(
-      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Parent</summary><div class="details-wrapper"><details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details>
-</div></details>
-',
+      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Parent</summary><div class="details-wrapper"><details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details></div></details>',
       '#attached' => array(
         'js' => array(
           array('type' => 'setting', 'data' => array('foo' => 'bar'))
@@ -660,9 +658,7 @@ function testDrupalRenderChildrenPostRenderCache() {
     $cached_parent_element = cache()->get(drupal_render_cid_create($element))->data;
     $cached_child_element = cache()->get(drupal_render_cid_create($element['child']))->data;
     $expected_parent_element = array(
-      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Parent</summary><div class="details-wrapper"><details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details>
-</div></details>
-',
+      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Parent</summary><div class="details-wrapper"><details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details></div></details>',
       '#attached' => array(
         'js' => array(
           array('type' => 'setting', 'data' => array('foo' => 'bar'))
@@ -682,8 +678,7 @@ function testDrupalRenderChildrenPostRenderCache() {
     );
     $this->assertIdentical($cached_parent_element, $expected_parent_element, 'The correct data is cached for the parent: the stored #markup and #attached properties are not affected by #post_render_cache callbacks.');
     $expected_child_element = array(
-      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details>
-',
+      '#markup' => '<details class="form-wrapper" open="open"><summary role="button" aria-expanded>Child</summary><div class="details-wrapper">Subchild</div></details>',
       '#attached' => array(
         'library' => array(
           array('system', 'drupal.collapse'),
diff --git a/core/modules/system/templates/details.html.twig b/core/modules/system/templates/details.html.twig
index aef051e..9a6e463 100644
--- a/core/modules/system/templates/details.html.twig
+++ b/core/modules/system/templates/details.html.twig
@@ -15,19 +15,21 @@
  * @ingroup themeable
  */
 #}
-<details{{ attributes }}>
-  {% if title %}
-    <summary{{ summary_attributes }}>{{ title }}</summary>
-  {% endif %}
-  <div class="details-wrapper">
-    {% if description %}
-      <div class="details-description">{{ description }}</div>
-    {% endif %}
-    {% if children %}
-      {{ children }}
-    {% endif %}
-    {% if value %}
-      {{ value }}
-    {% endif %}
-  </div>
-</details>
+{% spaceless %}
+  <details{{ attributes }}>
+    {%- if title -%}
+      <summary{{ summary_attributes }}>{{ title }}</summary>
+    {%- endif -%}
+    <div class="details-wrapper">
+      {%- if description -%}
+        <div class="details-description">{{ description }}</div>
+      {%- endif -%}
+      {%- if children -%}
+        {{ children }}
+      {%- endif -%}
+      {%- if value -%}
+        {{ value }}
+      {%- endif -%}
+    </div>
+  </details>
+{% endspaceless %}