Description:
------------
OSes: OSX (version 10.11.5), Ubuntu 14.04.3 LTS, CentOS release 6.5 (Final)
PHP versions: 5.5, 5.6, 7.0

When implementing a simple singly linked list in PHP I get a segfault if I try to add too many items to the list. To define too many: the sample code attached could cope with 29,000 items on my machine but segfaults with 30,000 items.

The interesting part is that if I first remove the items from the list, eg. with $this->head = $this->head->getNext() (method excluded from the sample code for brevity) then everything works as expected and I can add items to the list till it fill up and I get "Fatal error: Uncaught RuntimeException: Stack overflow.", which is expected.

If I add __destruct() { $this->head = null; } to LinkedList and set a breakpoint there it will segfault when I execute that line.

Test script:
---------------
<?php
class Node {
    private $next;

    public function setNext(Node $node = null) {
        $this->next = $node;
        return $this;
    }
}

class LinkedList {
    private $head;

    public function addNode() {
        $this->head = (new Node())->setNext($this->head);
    }
}

$ll = new LinkedList();
for ($i = 0; $i < 100000; $i++) {
    $ll->addNode();
}

Expected result:
----------------
no output

Actual result:
--------------
'php test.php' terminated by signal SIGSEGV (Address boundary error)