Description:
------------
Creating instance of \SoapClient with incorrect path to WSDL file causing incorrect work of SimpleXMLElement::asXML method, in completely different object.

I ran script below in PHP: 5.5 (Debian), 5.6 (Windows) and 7.0.6 (Windows) and 7.0.5 (CentOS). I got errors only in PHP 7 on Windows and Linux.

I've made one change in php.ini - I was activated php_soap extension.


Test script:
---------------
<?php
 
libxml_use_internal_errors(true);
 
try {
    $a = new \SoapClient('fake/wsdl');
} catch (\SoapFault $ex) {
}
 
$source = simplexml_load_string("<xml></xml>");
var_dump($source->asXML('example.xml')); // should be true
var_dump(libxml_get_errors()); // should be one error, but there are 2

Expected result:
----------------
bool(true)
array(1) {
  [0]=>
  object(LibXMLError)#3 (6) {
    ["level"]=>
    int(1)
    ["code"]=>
    int(1549)
    ["column"]=>
    int(0)
    ["message"]=>
    string(43) "failed to load external entity "fake/wsdl"
"
    ["file"]=>
    string(0) ""
    ["line"]=>
    int(0)
  }
}
PHP Fatal error:  SOAP-ERROR: Parsing WSDL: Couldn't load from 'fake/wsdl' : failed to load external entity "fake/wsdl"
 in C:\a.php on line 6


Actual result:
--------------
bool(false)
array(2) {
  [0]=>
  object(LibXMLError)#3 (6) {
    ["level"]=>
    int(1)
    ["code"]=>
    int(1549)
    ["column"]=>
    int(0)
    ["message"]=>
    string(43) "failed to load external entity "fake/wsdl"
"
    ["file"]=>
    string(0) ""
    ["line"]=>
    int(0)
  }
  [1]=>
  object(LibXMLError)#4 (6) {
    ["level"]=>
    int(2)
    ["code"]=>
    int(1545)
    ["column"]=>
    int(0)
    ["message"]=>
    string(11) "flush error"
    ["file"]=>
    string(0) ""
    ["line"]=>
    int(0)
  }
}
PHP Fatal error:  SOAP-ERROR: Parsing WSDL: Couldn't load from 'fake/wsdl' : failed to load external entity "fake/wsdl"
 in C:\a.php on line 6