new ArrayObject($targetObject) allows setting typed properties to invalid types

[TysonAndre]

Description

The following code:

<?php
class C {
    public int $intProp;
}
$c = new C();
$a = new ArrayObject($c);
$a['intProp'] = [];
var_export($c);

// Alternate snippet that would be an Uncaught TypeError: Cannot assign array to property C::$intProp of type int
// unset($c->intProp);
// $c->intProp = [];

Resulted in this output:

\C::__set_state(array(
   'intProp' => 
  array (
  ),
))

But I expected this output instead:

Uncaught TypeError: Cannot assign array to property C::$intProp of type int

Related to #9432
Discovered while reviewing #9354

PHP Version

PHP 7.4+

Operating System

No response

[cmb69]

https://3v4l.org/7vGT3 – ugh.