Resolving VUFIND-802 (HorizonXMLAPI bug fixes).

Thanks to Jay Roos.

config/vufind/HorizonXMLAPI.ini

@@ -22,7 +22,7 @@ dateformat = "m/d/Y"
 [Holds]
 ; HMACKeys - A list of hold form element names that will be analyzed for consistency
 ; during hold form processing. Most users should not need to change this setting.
-HMACKeys = item_id
+HMACKeys = item_id:id:level
 
 ; notify - The method by which users are notified when their hold / request is 
 ; available. Must correspond with a Horizon system setting.

module/VuFind/src/VuFind/ILS/Driver/HorizonXMLAPI.php

@@ -456,7 +456,7 @@ class HorizonXMLAPI extends Horizon implements \VuFindHttp\HttpServiceAwareInter
 
             // set itemkey only if available and level is not title-level
             if ($itemData['id'] != '' && $itemData['level'] != 'title') {
-                $params += array("itemkey" => $itemData);
+                $params += array("itemkey" => $itemData['id']);
             }
 
             $initResponse = $this->makeRequest($params);