From d0f8d4451682c840955646122fa1d20e92a1bc1f Mon Sep 17 00:00:00 2001
From: Nathan Coad <nathan@thecoads.com>
Date: Tue, 27 Jun 2017 19:04:52 +1000
Subject: [PATCH] handle mailsystem register/cleanup better

---
 booking.install | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/booking.install b/booking.install
index 186adda..b5b5c36 100644
--- a/booking.install
+++ b/booking.install
@@ -695,11 +695,9 @@ function booking_uninstall() {
   */
 function booking_enable() {
 	drupal_set_message($message = t('The Booking System module was successfully enabled.'), $type = 'status');
-	variable_set('mail_system', array('default-system' => 'DefaultMailSystem', 'booking' => 'BookingMailSystem'));
-	//let MIME Mail know that we can send html emails
-	mailsystem_set(array(
-    'booking' => 'BookingMailSystem',
-  ));
+  $current = variable_get('mail_system', array('default-system' => 'DefaultMailSystem'));
+  $addition = array('booking' => 'BookingMailSystem');
+  variable_set('mail_system', array_merge($current, $addition));
 }
 
 /**
@@ -707,11 +705,9 @@ function booking_enable() {
   */
 function booking_disable() {
 	drupal_set_message($message = t('The Booking System module was successfully disabled.'), $type = 'status');
-	variable_set('mail_system', array('default-system' => 'DefaultMailSystem'));
-	//clean up our entry about mailsystems
-	mailsystem_clear(array(
-    'booking' => 'BookingMailSystem',
-  ));
+  $mail_system = variable_get('mail_system', array('default-system' => 'DefaultMailSystem'));
+  unset($mail_system['booking']);
+  variable_set('mail_system', $mail_system);
 }
 
 /**