Don't show this menu for users who are not logged in.

git-svn-id: https://develop.svn.wordpress.org/trunk@18686 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/admin-bar.php

@@ -100,6 +100,9 @@ function wp_admin_bar_my_account_menu( $wp_admin_bar ) {
  * @since 3.3.0
  */
 function wp_admin_bar_blog_front_menu( $wp_admin_bar ) {
+	if ( ! is_user_logged_in() )
+		return;
+
 	$blogname = get_bloginfo('name');
 
 	if ( empty( $blogname ) )