Web Audio Evaluation Tool

... as a consequence, the xmlhttp.responseXML is always empty.
setting

                xmlhttp.overrideMimeType('text/xml');

as I did for #1616 does note seem to work.
I had to use the stronger workaround suggested here http://stackoverflow.com/questions/3781387/responsexml-always-null :

var parser = new DOMParser();
var xmlDoc = parser.parseFromString(xmlhttp.responseText, "application/xml");

This works. patch file attached

maybe this is a php-version- or php-configuration-dependent issue?
It happens to me when using apache2 and
PHP 5.5.30 (cli) (built: Oct 23 2015 17:21:45)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies
on MacOS El Capitan

(when running the server in python it works fine.)