1--TEST--
2ob_start(): ensure buffers can't be added from within callback.
3--FILE--
4<?php
5
6/*
7 * Function is implemented in main/output.c
8*/
9
10function f($str) {
11    ob_start();
12    echo "hello";
13    ob_end_flush();
14    return $str;
15}
16
17
18var_dump(ob_start('f'));
19echo "done";
20?>
21--EXPECTF--
22Fatal error: ob_start(): Cannot use output buffering in output buffering display handlers in %s on line %d
23