Assertion failure in Zend/zend_weakrefs.c:646

[YuanchengJiang]

Description

The following code:

<?php
$map = new WeakMap();
$fusion = $map;
$obj = new stdClass;
$ao = new ArrayObject($obj);
$i = $fusion->getIterator();
$ao->offsetUnset($i->key());

Resulted in this output:

/php-src/Zend/zend_weakrefs.c:646: void zend_weakmap_iterator_get_current_key(zend_object_iterator *, zval *): Assertion `0 && "Must have integer key"' failed.
Aborted (core dumped)

PHP Version

nightly

Operating System

ubuntu 22.04

[nielsdos]

See also #15775 (comment)
IMO We should just yeet this class ASAP

[cmb69]

See php/doc-en#3858 (a humble first step).

[arnaud-lb]

Is the class also problematic when backed by arrays? (new ArrayObject([]))

I've seen it used as pass-by-ref arrays. Until now I was convinced this was the primary use-case, and that objects support had been added because "why not". Looking at the history, it was added in 173cb1436fb5 ("Add class spl_array which is an array wrapper"). It was originally named spl_array, but later renamed ArrayClass, and ultimately ArrayObject.

If that part is relatively sane, can we just discourage the use of objects as backing store?

[cmb69]

Good point @arnaud-lb! I guess you're right, and there are no general issues when wrapping arrays (and also about the history of the class, and especially the "why not" comment). Thus, I've just submitted php/doc-en#3867.