Segfault in mb_strrpos / mb_strripos when using negative offset and ASCII encoding

[rgeraads]

Description

The following code:

<?php
var_dump(mb_strrpos('foo', 'foo', -1, 'ASCII'));
var_dump(mb_strripos('foo', 'foo', -1, 'ASCII'));

Resulted in this output:

Segmentation fault

But I expected this output instead:

bool(false)
bool(false)

https://3v4l.org/BlLRn

PHP Version

PHP 8.2.0

Operating System

No response