commit 42dd1b8c2e91979dd0ce2214abfee24cf0817540
Author: Joel Pittet <joel@pittet.ca>
Date:   Sat May 18 18:12:47 2013 -0700

    #38

diff --git a/core/modules/overlay/overlay.module b/core/modules/overlay/overlay.module
index 1566740..9765b76 100644
--- a/core/modules/overlay/overlay.module
+++ b/core/modules/overlay/overlay.module
@@ -521,8 +521,12 @@ function template_preprocess_overlay(&$variables) {
   $variables['disable_overlay'] = overlay_disable_message();
 
   // Add atrributes for the overlay container.
+  $variables['attributes']['id'] = 'overlay';
   $variables['attributes']['class'][] = 'overlay';
+  // Add attributes for the overlay title.
+  $variables['title_attributes']['id'] = 'overlay-title';
   // Add attributes for the overlay content.
+  $variables['content_attributes']['id'] = 'overlay-content';
   $variables['content_attributes']['class'][] = 'clearfix';
 }
 
diff --git a/core/modules/overlay/templates/overlay.html.twig b/core/modules/overlay/templates/overlay.html.twig
index 10b6cdf..f54633e 100644
--- a/core/modules/overlay/templates/overlay.html.twig
+++ b/core/modules/overlay/templates/overlay.html.twig
@@ -4,6 +4,9 @@
  * Default theme implementation to display a page in the overlay.
  *
  * Available variables:
+ * - attributes: HTML attributes for the containing element.
+ * - content_attributes: HTML attributes for the content.
+ * - title_attributes: HTML attributes for the title.
  * - title: The (sanitized) title of the page.
  * - page: The rendered page content.
  * - tabs: Tabs linking to any sub-pages beneath the current page (e.g., the
@@ -17,10 +20,10 @@
  */
 #}
 {{ disable_overlay }}
-<div id="overlay"{{ attributes }}>
+<div{{ attributes }}>
   <div id="overlay-titlebar" class="clearfix">
     <div id="overlay-title-wrapper" class="clearfix">
-      <h1 id="overlay-title"{{ title_attributes }}>{{ title }}</h1>
+      <h1{{ title_attributes }}>{{ title }}</h1>
     </div>
     <div id="overlay-close-wrapper">
       <a id="overlay-close" href="#" class="overlay-close" role="button" aria-controls="overlay-content"><span class="element-invisible">{{ 'Close overlay'|t }}</span></a>
@@ -29,7 +32,7 @@
       <h2 class="element-invisible">{{ 'Primary tabs'|t }}</h2><ul id="overlay-tabs">{{ tabs }}</ul>
     {% endif %}
   </div>
-  <div id="overlay-content"{{ content_attributes }}>
+  <div{{ content_attributes }}>
     {{ page }}
   </div>
 </div>