commit c1b166795816424dab565e7e5ac53f67f80a42d8
Author: Joel Pittet <joel@pittet.ca>
Date:   Wed Jan 29 00:31:12 2014 -0800

    touchups

diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index c89b979..f917504 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2023,8 +2023,6 @@ function _template_preprocess_default_variables() {
   // Variables that don't depend on a database connection.
   $variables = array(
     'attributes' => array(),
-    'title_attributes' => array(),
-    'content_attributes' => array(),
     'title_prefix' => array(),
     'title_suffix' => array(),
     'db_is_active' => !defined('MAINTENANCE_MODE'),
diff --git a/core/lib/Drupal/Core/Template/Attribute.php b/core/lib/Drupal/Core/Template/Attribute.php
index 473b31a..1ebdd9f 100644
--- a/core/lib/Drupal/Core/Template/Attribute.php
+++ b/core/lib/Drupal/Core/Template/Attribute.php
@@ -83,6 +83,9 @@ protected function createAttributeValue($name, $value) {
     if (is_array($value)) {
       $value = new AttributeArray($name, $value);
     }
+    elseif ($name == 'class') {
+      $value = new AttributeArray($name, array($value));
+    }
     elseif (is_bool($value)) {
       $value = new AttributeBoolean($name, $value);
     }
diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index ef38caf..ef155dc 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -318,5 +318,4 @@ function aggregator_preprocess_block(&$variables) {
   if ($variables['configuration']['module'] == 'aggregator') {
     $variables['attributes']['role'] = 'complementary';
   }
-  $variables['attributes'] = new Attribute($variables['attributes']);
 }
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index d7c4ae0..c25ee65 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -503,14 +503,21 @@ function template_preprocess_block(&$variables) {
 
   // Add default class for block content.
   $variables['content_attributes']['class'][] = 'content';
-  $variables['content_attributes'] = new Attribute($variables['content_attributes']);
 
   // Create a valid HTML ID and make sure it is unique.
   if ($id = $variables['elements']['#block']->id()) {
     $variables['attributes']['id'] = drupal_html_id('block-' . $id);
   }
-  $variables['title_attributes'] = '';
-  $variables['attributes'] = new Attribute($variables['attributes']);
+
+  static $default_attributes;
+  if (!isset($default_attributes)) {
+    $default_attributes = new Attribute;
+  }
+
+  // For best performance, we only instantiate Attribute objects when needed.
+  $variables['attributes'] = isset($variables['attributes']) ? new Attribute($variables['attributes']) : clone $default_attributes;
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : clone $default_attributes;
+  $variables['content_attributes'] = isset($variables['content_attributes']) ? new Attribute($variables['content_attributes']) : clone $default_attributes;
 }
 
 /**
diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 89483be..0457488 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -598,7 +598,6 @@ function book_preprocess_block(&$variables) {
   if ($variables['configuration']['module'] == 'book') {
     $variables['attributes']['role'] = 'navigation';
   }
-  $variables['attributes'] = new Attribute($variables['attributes']);
 }
 
 /**
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 43de7c2..6bef9db 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1309,7 +1309,6 @@ function comment_preprocess_block(&$variables) {
   if ($variables['configuration']['module'] == 'comment') {
     $variables['attributes']['role'] = 'navigation';
   }
-  $variables['attributes'] = new Attribute($variables['attributes']);
 }
 
 /**
@@ -1459,11 +1458,18 @@ function template_preprocess_comment(&$variables) {
 
   // Add comment author user ID. Necessary for the comment-by-viewer library.
   $variables['attributes']['data-comment-user-id'] = $comment->uid->value;
-  $variables['attributes'] = new Attribute($variables['attributes']);
 
   $variables['content_attributes']['class'][] = 'content';
-  $variables['content_attributes'] = new Attribute($variables['content_attributes']);
 
+  static $default_attributes;
+  if (!isset($default_attributes)) {
+    $default_attributes = new Attribute;
+  }
+
+  // For best performance, we only instantiate Attribute objects when needed.
+  $variables['attributes'] = isset($variables['attributes']) ? new Attribute($variables['attributes']) : clone $default_attributes;
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : clone $default_attributes;
+  $variables['content_attributes'] = isset($variables['content_attributes']) ? new Attribute($variables['content_attributes']) : clone $default_attributes;
 }
 
 /**
diff --git a/core/modules/contextual/contextual.module b/core/modules/contextual/contextual.module
index ecb19b4..3fd2cb9 100644
--- a/core/modules/contextual/contextual.module
+++ b/core/modules/contextual/contextual.module
@@ -196,7 +196,6 @@ function contextual_preprocess(&$variables, $hook, $info) {
   if (isset($element) && is_array($element) && !empty($element['#contextual_links'])) {
     // Mark this element as potentially having contextual links attached to it.
     $variables['attributes']['class'][] = 'contextual-region';
-    $variables['attributes'] = new Attribute($variables['attributes']);
 
     // Renders a contextual links placeholder unconditionally, thus not breaking
     // the render cache. Although the empty placeholder is rendered for all
diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index 5200fc7..0c521f5 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -556,16 +556,11 @@ function template_preprocess_field(&$variables, $hook) {
   if (!isset($default_attributes)) {
     $default_attributes = new Attribute;
   }
-  // The default theme implementation for fields is a function.
-  // template_preprocess() (which initializes the attributes, title_attributes,
-  // and content_attributes arrays) does not run for theme function
-  // implementations. Additionally, Attribute objects for the three variables
-  // below only get instantiated for template file implementations, and we need
-  // Attribute objects for printing in both theme functions and template files.
+
   // For best performance, we only instantiate Attribute objects when needed.
-  $variables['attributes'] = clone $default_attributes;
-  $variables['title_attributes'] = clone($default_attributes);
-  $variables['content_attributes'] = clone($default_attributes);
+  $variables['attributes'] = isset($variables['attributes']) ? new Attribute($variables['attributes']) : clone $default_attributes;
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : clone $default_attributes;
+  $variables['content_attributes'] = isset($variables['content_attributes']) ? new Attribute($variables['content_attributes']) : clone $default_attributes;
 
   // Modules (e.g., rdf.module) can add field item attributes (to
   // $item->_attributes) within hook_entity_prepare_view(). Some field
@@ -575,7 +570,7 @@ function template_preprocess_field(&$variables, $hook) {
   // formatters leave them within $element['#items'][$delta]['_attributes'] to
   // be rendered on the item wrappers provided by theme_field().
   foreach ($variables['items'] as $delta => $item) {
-    $variables['item_attributes'][$delta] = !empty($element['#items'][$delta]->_attributes) ? new Attribute($element['#items'][$delta]->_attributes) : clone($default_attributes);
+    $variables['item_attributes'][$delta] = !empty($element['#items'][$delta]->_attributes) ? new Attribute($element['#items'][$delta]->_attributes) : clone $default_attributes;
   }
 }
 
diff --git a/core/modules/forum/forum.module b/core/modules/forum/forum.module
index 8c495b9b..538d6b3 100644
--- a/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -574,7 +574,6 @@ function forum_block_view_pre_render($elements) {
 function forum_preprocess_block(&$variables) {
   if ($variables['configuration']['module'] == 'forum') {
     $variables['attributes']['role'] = 'navigation';
-    $variables['attributes'] = new Attribute($variables['attributes']);
   }
 }
 
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index c12507f..eda70ec 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -702,9 +702,18 @@ function template_preprocess_node(&$variables) {
   if (isset($variables['preview'])) {
     $variables['attributes']['class'][] = 'preview';
   }
-  $variables['attributes'] = new Attribute($variables['attributes']);
   $variables['content_attributes']['class'][] = 'content';
-  $variables['content_attributes'] = new Attribute($variables['content_attributes']);
+
+  static $default_attributes;
+  if (!isset($default_attributes)) {
+    $default_attributes = new Attribute;
+  }
+
+  // For best performance, we only instantiate Attribute objects when needed.
+  $variables['attributes'] = isset($variables['attributes']) ? new Attribute($variables['attributes']) : clone $default_attributes;
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : clone $default_attributes;
+  $variables['content_attributes'] = isset($variables['content_attributes']) ? new Attribute($variables['content_attributes']) : clone $default_attributes;
+
 }
 
 /**
diff --git a/core/modules/rdf/rdf.module b/core/modules/rdf/rdf.module
index e229e39..d2fa4ba 100644
--- a/core/modules/rdf/rdf.module
+++ b/core/modules/rdf/rdf.module
@@ -478,7 +478,6 @@ function rdf_preprocess_comment(&$variables) {
     // is a literal.
     $variables['title_attributes']['property'] = $title_mapping['properties'];
     $variables['title_attributes']['datatype'] = '';
-    $variables['title_attributes'] = new Attribute($variables['title_attributes']);
   }
 
   // Annotates the parent relationship between the current comment and the node
@@ -545,7 +544,6 @@ function rdf_preprocess_image(&$variables) {
   // to get 'foaf:Image' because image does not have its own entity type or
   // bundle.
   $variables['attributes']['typeof'] = array('foaf:Image');
-  $variables['attributes'] = new Attribute($variables['attributes']);
 }
 
 /**
diff --git a/core/modules/search/search.module b/core/modules/search/search.module
index a89c725..25f9825 100644
--- a/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -5,7 +5,6 @@
  * Enables site-wide keyword searching.
  */
 
-use Drupal\Core\Template\Attribute;
 use Drupal\Component\Utility\Unicode;
 
 /**
@@ -140,9 +139,7 @@ function search_permission() {
 function search_preprocess_block(&$variables) {
   if ($variables['plugin_id'] == 'search_form_block') {
     $variables['attributes']['role'] = 'search';
-    $variables['attributes'] = new Attribute($variables['attributes']);
     $variables['content_attributes']['class'][] = 'container-inline';
-    $variables['content_attributes'] = new Attribute($variables['content_attributes']);
   }
 }
 
diff --git a/core/modules/search/search.pages.inc b/core/modules/search/search.pages.inc
index a9c6326..b1ef5d9 100644
--- a/core/modules/search/search.pages.inc
+++ b/core/modules/search/search.pages.inc
@@ -68,9 +68,7 @@ function template_preprocess_search_result(&$variables) {
   $variables['title'] = check_plain($result['title']);
   if (isset($result['language']) && $result['language'] != $language_interface->id && $result['language'] != Language::LANGCODE_NOT_SPECIFIED) {
     $variables['title_attributes']['lang'] = $result['language'];
-    $variables['title_attributes'] = new Attribute($variables['title_attributes']);
     $variables['content_attributes']['lang'] = $result['language'];
-    $variables['content_attributes'] = new Attribute($variables['content_attributes']);
   }
 
   $info = array();
@@ -91,5 +89,15 @@ function template_preprocess_search_result(&$variables) {
   // Provide separated and grouped meta information..
   $variables['info_split'] = $info;
   $variables['info'] = implode(' - ', $info);
+
+  static $default_attributes;
+  if (!isset($default_attributes)) {
+    $default_attributes = new Attribute;
+  }
+
+  // For best performance, we only instantiate Attribute objects when needed.
+  $variables['attributes'] = isset($variables['attributes']) ? new Attribute($variables['attributes']) : clone $default_attributes;
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : clone $default_attributes;
+  $variables['content_attributes'] = isset($variables['content_attributes']) ? new Attribute($variables['content_attributes']) : clone $default_attributes;
 }
 
diff --git a/core/modules/toolbar/toolbar.module b/core/modules/toolbar/toolbar.module
index f35d4ae..8ab4736 100644
--- a/core/modules/toolbar/toolbar.module
+++ b/core/modules/toolbar/toolbar.module
@@ -221,7 +221,7 @@ function template_preprocess_toolbar(&$variables) {
   $element = $variables['element'];
 
   // Prepare the toolbar attributes.
-  $variables['attributes'] = $element['#attributes'];
+  $variables['attributes'] = new Attribute($element['#attributes']);
   $variables['toolbar_attributes'] = new Attribute($element['#bar']['#attributes']);
   $variables['toolbar_heading'] = $element['#bar']['#heading'];
 
diff --git a/core/modules/views/views.theme.inc b/core/modules/views/views.theme.inc
index 9a9d8fc..48dd2c9 100644
--- a/core/modules/views/views.theme.inc
+++ b/core/modules/views/views.theme.inc
@@ -752,6 +752,8 @@ function template_preprocess_views_view_table(&$variables) {
     // This is needed to target tables constructed by this function.
     $variables['attributes']['class'][] = 'responsive-enabled';
   }
+
+  $variables['attributes'] = new Attribute($variables['#attributes']);
 }
 
 /**
@@ -875,6 +877,7 @@ function template_preprocess_views_view_grid(&$variables) {
 
   // Add items to the variables array.
   $variables['items'] = $items;
+  $variables['attributes'] = new Attribute($variables['#attributes']);
 }
 
 /**
@@ -921,6 +924,7 @@ function template_preprocess_views_view_unformatted(&$variables) {
     }
     $variables['rows'][$id]['attributes'] = new Attribute($variables['rows'][$id]['attributes']);
   }
+  $variables['attributes'] = new Attribute($variables['#attributes']);
 }
 
 /**
diff --git a/core/modules/views_ui/views_ui.theme.inc b/core/modules/views_ui/views_ui.theme.inc
index fa4f563..776e49f 100644
--- a/core/modules/views_ui/views_ui.theme.inc
+++ b/core/modules/views_ui/views_ui.theme.inc
@@ -76,6 +76,8 @@ function template_preprocess_views_ui_display_tab_bucket(&$variables) {
   $variables['content'] = $element['#children'];
   $variables['title'] = $element['#title'];
   $variables['actions'] = !empty($element['#actions']) ? $element['#actions'] : array();
+
+  $variables['attributes'] = new Attribute($variables['attributes']);
 }
 
 /**
diff --git a/core/themes/bartik/bartik.theme b/core/themes/bartik/bartik.theme
index 5950c60..ab4683c 100644
--- a/core/themes/bartik/bartik.theme
+++ b/core/themes/bartik/bartik.theme
@@ -5,7 +5,6 @@
  * Functions to support theming in the Bartik theme.
  */
 
-use Drupal\Core\Template\Attribute;
 use Drupal\Core\Template\RenderWrapper;
 
 /**
@@ -92,8 +91,6 @@ function bartik_preprocess_page(&$variables) {
     // Make sure the shortcut link is the first item in title_suffix.
     $variables['title_suffix']['add_or_remove_shortcut']['#weight'] = -100;
   }
-
-  $variables['attributes'] = new Attribute($variables['attributes']);
 }
 
 /**
@@ -196,7 +193,7 @@ function bartik_field__taxonomy_term_reference($variables) {
 
   // Render the top-level DIV.
   $variables['attributes']['class'][] = 'clearfix';
-  $output = '<div ' . new Attribute($variables['attributes']) . '>' . $output . '</div>';
+  $output = '<div ' . $variables['attributes'] . '>' . $output . '</div>';
 
   return $output;
 }