Description:
------------
On Windows the file property of libXMLError objects contains file:
URIs. These are invalid for current versions of PHP (tested 5.6.9)
with current versions of libxml2 (tested 2.9.2). It worked as
expected with PHP 5.4.19 and libxml2 2.7.8.

This bug affects, for instance, the configure script of the PHP
documentation.

I don't know if that's an issue with libxml2 or PHP's wrapper.

Test script:
---------------
<?php

libxml_use_internal_errors(true);
$doc = new DomDocument();
// the file xml-error.xml is supposed to have at least one error
$doc->load('xml-error.xml');
$errors = libxml_get_errors();
var_dump($errors[0]->file);

?>

Expected result:
----------------
string(43) "file:///C:/Users/cmb/php/bugs/xml-error.xml"

Actual result:
--------------
string(41) "file:/C:/Users/cmb/php/bugs/xml-error.xml"