fix prepare event_link for events with alternate reg page

gistfile1.txt

function espresso_prepare_event_link_fixed ($payment_data) {
	global $wpdb;
	remove_filter('filter_hook_espresso_prepare_event_link', 'espresso_prepare_event_link');
	$sql = "SELECT  ea.event_id, ed.event_name, ed.externalURL FROM " . EVENTS_ATTENDEE_TABLE . " ea";
	$sql .= " JOIN " . EVENTS_DETAIL_TABLE . " ed ON ed.id=ea.event_id";
	$sql .= " WHERE ea.attendee_session='" . $payment_data['attendee_session'] . "'";
	$events = $wpdb->get_results($sql, OBJECT_K);
	$payment_data['event_link'] = '';
	foreach ($events as $event) {
		if (empty($event->externalURL)) {
			$event_url = espresso_reg_url($event->event_id);
		} else {
			$event_url = $event->externalURL;
		}
		$payment_data['event_link'] .= '<a href="' . $event_url . '">' . $event->event_name . '</a><br />';
	}
	return $payment_data;
}
add_filter('filter_hook_espresso_prepare_event_link', 'espresso_prepare_event_link_fixed', 5);