Using `SessionHandler` doesn't always close session file

[cs278]

Description

The following code:

<?php

session_set_save_handler(new \SessionHandler, true);

session_start([
    'save_path' => __DIR__,
]);

$_SESSION['test'] = function () {};

If you make a request to this you'll see a fatal error due to the serialization failing, if you try and make another request the file is still locked and the request hangs waiting for the lock to be released. Removing the session_set_save_handler() is sufficient to fix the problem. From what I can tell ps_close_user is called but it never appears to make the call to SessionHandler::close().

I've managed to replicate this behaviour on FPM (ZTS and NTS) and CLI server.

I've written a test: 88f32f4

PHP Version

8.3.11 and 8.3.13-dev

Operating System

Debian/Ubuntu

[nielsdos]

This happens because eventually call_user_function is used to call the close method, but call_user_function never makes the call if an exception is already pending because it would result in unstable execution otherwise. Ideally the lock would get released by another cleanup mechanism.