Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.920
diff -u -p -r1.920 comment.module
--- modules/comment/comment.module	23 Nov 2010 06:02:06 -0000	1.920
+++ modules/comment/comment.module	23 Nov 2010 12:02:19 -0000
@@ -1894,7 +1894,7 @@ function comment_form($form, &$form_stat
       $author = $user->name;
     }
     else {
-      $author = ($comment->name ? $comment->name : variable_get('anonymous', t('Anonymous')));
+      $author = ($comment->name ? $comment->name : '');
     }
     $status = (user_access('skip comment approval') ? COMMENT_PUBLISHED : COMMENT_NOT_PUBLISHED);
     $date = '';
@@ -2139,13 +2139,19 @@ function comment_submit($comment) {
   if (empty($comment->date)) {
     $comment->date = 'now';
   }
-
   $comment->created = strtotime($comment->date);
   $comment->changed = REQUEST_TIME;
 
+  // If the comment was posted by a registered user, assign the author's ID.
+  // @todo Too fragile. Should be prepared and stored in comment_form() already.
   if (!$comment->is_anonymous && !empty($comment->name) && ($account = user_load_by_name($comment->name))) {
     $comment->uid = $account->uid;
   }
+  // If the comment was posted by an anonymous user and no author name was
+  // required, use "Anonymous" by default.
+  if ($comment->is_anonymous && (!isset($comment->name) || $comment->name === '')) {
+    $comment->name = variable_get('anonymous', t('Anonymous'));
+  }
 
   // Validate the comment's subject. If not specified, extract from comment body.
   if (trim($comment->subject) == '') {