iterator_count() on an SplFileObject runs endlessly

[pilif]

Description

The following code:

<?php

touch("/tmp/empty");
var_dump(iterator_count(new SplFileObject("/tmp/empty", "r")));

Resulted in this output:

(None. Script runs forever)

But I expected this output instead:

int(0)

It fails on files of any size, but this is the simplest I can reproduce the problem with.

Can reproduce this all the way to PHP 5.6 which is the earliest version I tried

PHP Version

PHP 8.4.12 (cli) (built: Sep  8 2025 21:17:50) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.4.12, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.12, Copyright (c), by Zend Technologies

Operating System

Tested under Linux and macOS

[pilif]

Might be a duplicate/other case of #8564, but much simpler to reproduce

[devnexen]

verified. it runs into an infinite loop in your case, incrementing the iterator count constantly.