PHP SOAP Client issue with "chameleon design pattern"

php-soap-client-chameleon-design-bug.php

<?php

function includedXsd($ns = null)
{
    $ns = $ns ? " xmlns=\"{$ns}\"" : '';

    return <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"{$ns}>
    <xsd:attributeGroup name="CurrencyAmountGroup">
        <xsd:attribute name="Amount" type="xsd:int"/>
        <xsd:attribute name="CurrencyCode" type="xsd:string"/>
    </xsd:attributeGroup>
    <xsd:complexType name="User">
        <xsd:attributeGroup ref="CurrencyAmountGroup" />
    </xsd:complexType>
</xsd:schema>
XML;
}

function importedXsd()
{
    return <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema targetNamespace="http://foo.bar/testserver/types" xmlns="http://foo.bar/testserver/types" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
	<xsd:include schemaLocation="bug-include.xsd" />
	<xsd:element name="User" type="User"/>
</xsd:schema>
XML;
}

function wsdl()
{
    return <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<definitions name="TestServer" targetNamespace="http://foo.bar/testserver" xmlns:tns="http://foo.bar/testserver"
             xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
             xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:ns="http://foo.bar/testserver/types">
    <types>
        <xsd:schema>
            <xsd:import namespace="http://foo.bar/testserver/types" schemaLocation="bug-import.xsd"/>
        </xsd:schema>
    </types>
    <message name="getUserRequest">
        <part name="id" type="xsd:id"/>
    </message>
    <message name="getUserResponse">
        <part name="userReturn" element="ns:User"/>
    </message>
    <portType name="TestServerPortType">
        <operation name="getUser">
            <input message="tns:getUserRequest"/>
            <output message="tns:getUserResponse"/>
        </operation>
    </portType>
    <binding name="TestServerBinding" type="tns:TestServerPortType">
        <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/>
        <operation name="getUser">
            <soap:operation soapAction="http://foo.bar/testserver/#getUser"/>
            <input>
                <soap:body use="literal" namespace="http://foo.bar/testserver"/>
            </input>
            <output>
                <soap:body use="literal" namespace="http://foo.bar/testserver"/>
            </output>
        </operation>
    </binding>
    <service name="TestServerService">
        <port name="TestServerPort" binding="tns:TestServerBinding">
            <soap:address location="http://localhost/wsdl-creator/TestClass.php"/>
        </port>
    </service>
</definitions>
XML;
}

class MockedSoapClient extends SoapClient
{
    public function __doRequest($request, $location, $action, $version, $one_way = 0)
    {
        return <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Header/>
    <soap:Body>
        <userReturn>
            <User Amount="123" CurrencyCode="USD"/>
        </userReturn>
    </soap:Body>
</soap:Envelope>
XML;
    }
}

function types($test, $ns = null)
{
    file_put_contents(__DIR__ . "/bug-include.xsd", includedXsd($ns));
    file_put_contents(__DIR__ . "/bug-import.xsd", importedXsd());
    file_put_contents(__DIR__ . "/bug.wsdl", wsdl());
    $client = new MockedSoapClient(__DIR__ . "/bug.wsdl", ['cache_wsdl' => WSDL_CACHE_NONE]);
    $response = $client->__soapCall('getUser', []);

    echo "$test\n";
    echo "TYPES: " . trim(implode(PHP_EOL, $client->__getTypes())) . PHP_EOL;
    echo "RESPONSE: " . json_encode($response, JSON_PRETTY_PRINT) . PHP_EOL;
    echo PHP_EOL;

    unlink(__DIR__ . "/bug-include.xsd");
    unlink(__DIR__ . "/bug-import.xsd");
    unlink(__DIR__ . "/bug.wsdl");
}

types('ACTUAL');
types('EXPECTED', 'http://foo.bar/testserver/types');

Inspired from @iRipVanWinkle https://gist.github.com/iRipVanWinkle/1313a4b86004d2bc1ca6cf0c64c5e8dd
Although the EXPECTED output "seems" to fix the issue (by modifying the XSD), it's expected to have the targetNamespace of the imported XSD propagated to the included XSD's namespace (not only its targetNamespace).