Undefined variable name is shortened when contains \0

[jorgsowa]

Description

The following code:

<?php

$a = "test\0test";

$$a;

https://3v4l.org/vSKAO#v8.3.1

Resulted in this output:

Warning: Undefined variable $test in /in/vSKAO on line 5

But I expected this output instead:

Warning: Undefined variable $test\0test in /in/vSKAO on line 5

Or even:

Warning: Undefined variable $testtest in /in/vSKAO on line 5

PHP Version

PHP 8.3.1

Operating System

No response

[nielsdos]

Essentially the same core issue as #13097
Might or might not be fixed with my PoC fix (#13097 (comment)) but haven't tested this yet.
EDIT: nope it doesn't because it uses zend_error with %s under the hood.