--TEST-- ob_start(): Ensure unerasable buffer cannot be erased by ob_clean(), ob_end_clean() or ob_end_flush(). --FILE-- --EXPECTF-- [callback:1]All of the following calls will fail to clean/remove the topmost buffer: Notice: ob_clean(): failed to delete buffer of callback (0) in %s on line 11 bool(false) Notice: ob_end_clean(): failed to discard buffer of callback (0) in %s on line 12 bool(false) Notice: ob_end_flush(): failed to send buffer of callback (0) in %s on line 13 bool(false) The OB nesting will still be 1 level deep: int(1)