Description:
------------
This commit[1] changed not just out-of-bounds offsets of strspn to throw ValueError, but lengths that exceed the string bounds as well.

Given that a positive $length argument functions as a max-length for the match attempt, the prior behavior of accepting a length beyond the string bounds makes sense and reverting to it would realign with substr whose length parameter serves a similar purpose.

Is something gained by breaking existing code and requiring:

strspn($subject, $mask, $start, min($length, strlen($subject) - $start))

where:

strspn($subject, $mask, $start, $length)

seemed to work fine as intended prior?

[1] https://github.com/php/php-src/commit/5d9ab53a5d53f11a18ae11ed31b17ff87c8d52a7

Test script:
---------------
<?php

var_dump(
    strspn("foo", "asdf", 0, 4),
    strspn("fffff", "asdf", 0, 4)
);

Expected result:
----------------
int(1)
int(4)

Actual result:
--------------
Fatal error: Uncaught ValueError: strspn(): Argument #4 ($length) must be contained in argument #1 ($str) in /in/J05AD:4