always return an array from find_all

web/includes/Frame.php

@@ -73,13 +73,14 @@ class Frame {
         $file = $backTrace[1]['file'];
         $line = $backTrace[1]['line'];
 				Error("Invalid value for limit($limit) passed to Frame::find from $file:$line");
-				return;
+				return array();
 			}
 		}
 		$results = dbFetchAll($sql, NULL, $values);
 		if ( $results ) {
 		  return array_map( function($id){ return new Frame($id); }, $results );
 		}
+    return array();
 	}
 
 	public static function find_one( $parameters = array() ) {