Minor - Adding validation to avoid warning message + documentation

main/inc/lib/group_portal_manager.lib.php

@@ -291,6 +291,13 @@ class GroupPortalManager
 
 	/**
 	 * Gets the group's members
+	 * @param int group id
+	 * @param bool show image or not of the group
+	 * @param array list of relation type use constants  
+	 * @param int from value
+	 * @param int limit 
+	 * @param array image configuration, i.e array('height'=>'20px', 'size'=> '20px')
+	 * @return array list of users in a group 
 	 */
 	public static function get_users_by_group($group_id, $with_image = false, $relation_type = array(), $from = 0, $limit = 15, $image_conf = array('size'=>USER_IMAGE_SIZE_MEDIUM,'height'=>80))
 	{
@@ -321,13 +328,14 @@ class GroupPortalManager
 				$new_relation_type[] ="'$rel'";
 			}
 			$relation_type 			= implode(',', $new_relation_type);
-			$where_relation_condition = "AND gu.relation_type IN ($relation_type) ";
+			if (!empty($relation_type))
+				$where_relation_condition = "AND gu.relation_type IN ($relation_type) ";
 		}
 
 		$sql="SELECT picture_uri as image, u.user_id, u.firstname, u.lastname, relation_type FROM $tbl_user u
 			INNER JOIN $table_group_rel_user gu
 			ON (gu.user_id = u.user_id) WHERE gu.group_id= $group_id $where_relation_condition ORDER BY relation_type, firstname LIMIT $from, $limit";
-
+		
 		$result=Database::query($sql);
 		$array = array();
 		while ($row = Database::fetch_array($result, 'ASSOC')) {