wp_admin_bar_shortlink_menu( WP_Admin_Bar $wp_admin_bar )

function wp_admin_bar_shortlink_menu( $wp_admin_bar ) {
	$short = wp_get_shortlink( 0, 'query' );
	$id = 'get-shortlink';

	if ( empty( $short ) )
		return;

	$html = '<input class="shortlink-input" type="text" readonly="readonly" value="' . esc_attr( $short ) . '" />';

	$wp_admin_bar->add_menu( array(
		'id' => $id,
		'title' => __( 'Shortlink' ),
		'href' => $short,
		'meta' => array( 'html' => $html ),
	) );
}