1--TEST--
2ob_start(): Ensure unerasable buffer cannot be accessed or erased by ob_get_clean().
3--FILE--
4<?php
5function callback($string) {
6    static $callback_invocations;
7    $callback_invocations++;
8    return "[callback:$callback_invocations]$string\n";
9}
10
11ob_start('callback', 0, false);
12
13echo "This call will obtain the content, but will not clean the buffer.";
14$str = ob_get_clean();
15var_dump($str);
16?>
17--EXPECTF--
18[callback:1]This call will obtain the content, but will not clean the buffer.
19Notice: ob_get_clean(): Failed to discard buffer of callback (0) in %s on line 11
20
21Notice: ob_get_clean(): Failed to delete buffer of callback (0) in %s on line 11
22string(65) "This call will obtain the content, but will not clean the buffer."
23