Signed Integer Overflow in pack()

[bendrissou]

Description

The following code:

<?php
pack('h2147483647', 1);
?>

Resulted in this output:

/home/program/ext/standard/pack.c:389:5: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /home/program/ext/standard/pack.c:389:5 in 

But I expected this output instead:

Warning: pack(): Type h: not enough characters in string in /home/bug-1.php on line 3

PHP Version

PHP 8.5.0-dev (cli) (built: Jun  4 2025 20:21:49) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.5.0-dev, Copyright (c) Zend Technologies

Operating System

Ubuntu 20.04