Segfault under Debian Jessie

• Patch

When I go to http://internal/tiki/tiki-user_preferences.php, as any logged-in user, I always get a PHP Segfault.

$ /usr/sbin/php5-fpm --version
PHP 5.6.13-0+deb8u1 (fpm-fcgi) (built: Sep  7 2015 13:38:29)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies
    with Xdebug v2.3.2, Copyright (c) 2002-2015, by Derick Rethans
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2015, by Zend Technologies

[global]
pid = /run/php5-fpm.pid
error_log = /var/log/php5-fpm.log
log_level = debug
include=/etc/php5/fpm/pool.d/*.conf

[www]
user = www-data
group = www-data
listen = /var/run/php5-fpm.sock
listen.owner = www-data
listen.group = www-data
pm = ondemand
pm.max_children = 12
chdir = /

server {
...
        client_max_body_size 16M;
        root /var/www/html;
        index index.php index.html index.htm index.nginx-debian.html;
        location ~ \.php$ {
                # fastcgi-php.conf has not been changed from debian jessie default
                include snippets/fastcgi-php.conf;
                fastcgi_pass unix:/var/run/php5-fpm.sock;
        }
...
}

When this segfault happens, I get a core dump of ~8GB, every time. I tried adding Xdebug, and got a trace that I am willing to share with anyone who wants to look. (148k gz, 97k xz, 3.2M uncompressed)