Index: branches/RC/core/units/general/helpers/priority_helper.php
===================================================================
diff -u -N -r9639 -r11576
--- branches/RC/core/units/general/helpers/priority_helper.php	(.../priority_helper.php)	(revision 9639)
+++ branches/RC/core/units/general/helpers/priority_helper.php	(.../priority_helper.php)	(revision 11576)
@@ -1,52 +1,57 @@
 <?php
 
 	class kPriorityHelper extends kHelper {
-	
-		
+
+
 		/**
 		 * Prepares options for priority dropdown
 		 *
 		 * @param kEvent $event
 		 * @param bool $is_new for newly created items add new priority to the end
 		 * @param string $constrain constrain for priority selection (if any)
-		 * 
+		 *
 		 */
 		function preparePriorities(&$event, $is_new = false, $constrain = '')
 		{
 			$object =& $event->getObject();
-			
+
 			$field_options = $object->GetFieldOptions('Priority');
 			$table_name = $this->Application->getUnitOption($event->Prefix, 'TableName');
-			
+
 			$sql = 'SELECT COUNT(*)
 					FROM '.$table_name;
 			if ($constrain) {
-				$sql .= ' WHERE '.$constrain;	
+				$sql .= ' WHERE '.$constrain;
 			}
-			
+
 			if (!isset($object->Fields['OldPriority'])) {
 				$object->VirtualFields['OldPriority'] = Array('type' => 'int', 'default' => 0);
 			}
-					
+
 			$items_count = $this->Conn->GetOne($sql);
+			$current_priority = is_a($object, 'kDBList') ? 0 : $object->GetDBField('Priority');
+
+			if ($is_new || $current_priority == -($items_count+1)) {
+				$items_count++;
+			}
+
 			if ($is_new) {
 				// add new item to the end of list
-				$items_count++;
 				$object->SetDBField('Priority', -$items_count);
 				$object->SetDBField('OldPriority', -$items_count);
 			}
 			else {
-				$object->SetDBField('OldPriority', $object->GetDBField('Priority'));
+				$object->SetDBField('OldPriority', $current_priority);
 			}
-			
+
 			for ($i = 1; $i <= $items_count; $i++) {
 				$field_options['options'][-$i] = $i;
 			}
-			
+
 			$object->SetFieldOptions('Priority', $field_options);
 			// storing prioriry right after load for comparing when updating
 		}
-		
+
 		/**
 		 * Updates priorities for changed items
 		 *
@@ -59,30 +64,33 @@
 		{
 			$id_field = $this->Application->getUnitOption($event->Prefix, 'IDField');
 			$table_name = $this->Application->getUnitOption($event->Prefix, 'TableName');
-			
+
 			$not_processed = array_keys($changes);
-			
+			if(!$not_processed || !getArrayValue($not_processed, 0)) {
+				return $not_processed;
+			}
+
 			$ids = array();
 			foreach ($changes as $id => $pair) {
 				array_push($ids, $id);
 				$constrain = isset($pair['parent']) ? 'ParentId = '.$pair['parent'].' AND ' : '';
-				
+
 				if ($pair['old'] == 'new') {
 					// replace 0 with newly created item id (from $new_ids mapping)
 					$not_processed[ array_search($id, $not_processed) ] = $new_ids[$id];
 					$id = $new_ids[$id];
-					
+
 					$sql = 'SELECT MIN(Priority)
 							FROM '.$table_name.'
 							WHERE '.$constrain.' '.$id_field.' NOT IN ('.implode(',', $not_processed).')';
 					$min_priority = (int)$this->Conn->GetOne($sql) - 1;
-					
+
 					if ($pair['new'] < $min_priority) {
 						$pair['new'] = $min_priority;
 					}
 					$pair['old'] = $min_priority;
 				}
-				
+
 				if ($pair['new'] < $pair['old']) {
 					$set = '	SET Priority = Priority + 1';
 					$where =' WHERE '.$constrain.'
@@ -108,12 +116,12 @@
 				$ids = array_merge($ids, $this->Conn->GetCol('SELECT '.$id_field.' FROM '.$table_name.$where));
 				$q = 'UPDATE '.$table_name.' '.$set.$where;
 				$this->Conn->Query($q);
-				
+
 				unset( $not_processed[array_search($id, $not_processed)] );
 			}
 			return $ids;
 		}
-		
+
 		/**
 		 * Recalculates priorities
 		 *
@@ -124,14 +132,14 @@
 		{
 			$id_field = $this->Application->getUnitOption($event->Prefix, 'IDField');
 			$table_name = $this->Application->getUnitOption($event->Prefix, 'TableName');
-			
+
 			$sql = 'SELECT '.$id_field.'
 					FROM '.$table_name.
 					($constrain ? ' WHERE '.$constrain : '').'
 					ORDER BY Priority DESC';
-			
+
 			$items = $this->Conn->GetCol($sql);
-			
+
 			foreach ($items as $item_number => $item_id) {
 				$sql = 'UPDATE '.$table_name.'
 						SET Priority = '.-($item_number + 1).'
@@ -140,6 +148,6 @@
 			}
 			return $items;
 		}
-		
+
 	}
 ?>
\ No newline at end of file