Index: units/helpers/priority_helper.php
===================================================================
--- units/helpers/priority_helper.php	(revision 15165)
+++ units/helpers/priority_helper.php	(working copy)
@@ -182,8 +182,11 @@
 		{
 			$id_field = $this->Application->getUnitOption($event->Prefix, 'IDField');
 			$table_name = $this->Application->getUnitOption($event->Prefix, 'TableName');
-			$constrain = $this->normalizeConstrain($constrain);
 
+			if ( $constrain ) {
+				$constrain = $this->normalizeConstrain($constrain);
+			}
+
 			if ( $this->Application->IsTempMode($event->Prefix, $event->Special) ) {
 				$table_name = $this->Application->GetTempName($table_name, 'prefix:' . $event->Prefix);
 			}
Index: units/priorites/priority_eh.php
===================================================================
--- units/priorites/priority_eh.php	(revision 15165)
+++ units/priorites/priority_eh.php	(working copy)
@@ -390,6 +390,7 @@
 	{
 		$constrain_event = new kEvent($event->MasterEvent->getPrefixSpecial() . ':OnGetConstrainInfo');
 		$constrain_event->setEventParam('actual_event', $event->Name);
+		$constrain_event->setEventParam('original_special', $event->MasterEvent->Special);
 		$constrain_event->setEventParam('original_event', $event->MasterEvent->Name);
 		$this->Application->HandleEvent($constrain_event);