Index: wp-includes/class-wp-admin-bar.php
===================================================================
--- wp-includes/class-wp-admin-bar.php	(revision 19156)
+++ wp-includes/class-wp-admin-bar.php	(working copy)
@@ -70,10 +70,15 @@
 		if ( func_num_args() >= 3 && is_string( func_get_arg(0) ) )
 			$args = array_merge( array( 'parent' => func_get_arg(0) ), func_get_arg(2) );
 
-		// Ensure we have a valid ID and title.
-		if ( empty( $args['title'] ) || empty( $args['id'] ) )
+		// Ensure we have a valid title.
+		if ( empty( $args['title'] ) )
 			return false;
 
+		if ( empty( $args['id'] ) ) {
+			_doing_it_wrong( __FUNCTION__, __( 'The menu ID should not be empty.' ), '3.3' );
+			$args['id'] = esc_attr( sanitize_title( trim( $args['title'] ) ) );
+		}
+
 		$defaults = array(
 			'id'       => false,
 			'title'    => false,