redirect canonical

gistfile1.txt

        // tack on any additional query vars
        $redirect['query'] = preg_replace( '#^\??&*?#', '', $redirect['query'] );
        if ( $redirect_url && !empty($redirect['query']) ) {
                parse_str( $redirect['query'], $_parsed_query );
                $redirect = @parse_url($redirect_url);

                if ( ! empty( $_parsed_query['name'] ) && ! empty( $redirect['query'] ) ) {
                        parse_str( $redirect['query'], $_parsed_redirect_query );

                        if ( empty( $_parsed_redirect_query['name'] ) )
                                unset( $_parsed_query['name'] );
                }

                $_parsed_query = rawurlencode_deep( $_parsed_query );
                $redirect_url = add_query_arg( $_parsed_query, $redirect_url );
        }