Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.914
diff -u -p -r1.914 comment.module
--- modules/comment/comment.module	12 Nov 2010 03:18:13 -0000	1.914
+++ modules/comment/comment.module	14 Nov 2010 17:59:09 -0000
@@ -2318,6 +2318,8 @@ function template_preprocess_comment_wra
   // Provide contextual information.
   $variables['node'] = $variables['content']['#node'];
   $variables['display_mode'] = variable_get('comment_default_mode_' . $variables['node']->type, COMMENT_MODE_THREADED);
+  // The comment form is optional and may not exist.
+  $variables['content'] += array('comment_form' => array());
 }
 
 /**