WSDL (service.xml):
-------------------
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:tns="http://127.0.0.1/soap/server.php?a=a&amp;b=b" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soap12="http://schemas.xmlsoap.org/wsdl/soap12/" name="TestService" targetNamespace="http://127.0.0.1/soap/server.php?a=a&amp;b=b">
    <types>
        <xsd:schema targetNamespace="http://127.0.0.1/soap/server.php?a=a&amp;b=b" />
    </types>
    <portType name="TestServicePort">
        <operation name="test">
            <documentation>test</documentation>
            <input message="tns:testIn" />
            <output message="tns:testOut" />
        </operation>
    </portType>
    <binding name="TestServiceBinding" type="tns:TestServicePort">
        <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http" />
        <operation name="test">
            <soap:operation soapAction="http://127.0.0.1/soap/server.php?a=a&amp;b=b#test" />
            <input>
                <soap:body use="encoded" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" namespace="http://127.0.0.1/soap/server.php?a=a&amp;b=b" />
            </input>
            <output>
                <soap:body use="encoded" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" namespace="http://127.0.0.1/soap/server.php?a=a&amp;b=b" />
            </output>
        </operation>
    </binding>
    <service name="TestServiceService">
        <port name="TestServicePort" binding="tns:TestServiceBinding">
            <soap:address location="http://127.0.0.1/soap/server.php?a=a&amp;b=b" />
        </port>
    </service>
    <message name="testIn" />
    <message name="testOut">
        <part name="return" type="xsd:string" />
    </message>
</definitions>
-------------------

Server:
-------------------
$wsdl   = './service.xml';
$server = new SoapServer($wsdl, array(
    'cache_wsdl' => WSDL_CACHE_NONE,
    ));

$server->setClass('TestService');
$server->handle();
-------------------

Client:
-------------------
$wsdl   = './service.xml';
$client = new SoapClient($wsdl, array(
    'trace'      => true,
    'exceptions' => true,
    'cache_wsdl' => WSDL_CACHE_NONE,
    ));

$client->test(); // ERROR: Bad Request
-------------------


Actual invalid request:
-------------
SOAPAction: "http://test.local/ipb/isengard/test/soap/server.php?a=a&b=b#test"

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
        xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
        xmlns:ns1="http://127.0.0.1/soap/server.php?a=a&b=b" <!-- !!!!! ERROR !!!!! -->
        xmlns:xsd="http://www.w3.org/2001/XMLSchema"
        xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
    SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
    <SOAP-ENV:Body>
        <ns1:test />
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>
------------

Must be:
------------
SOAPAction: "http://test.local/ipb/isengard/test/soap/server.php?a=a&b=b#test"

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
        xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
        xmlns:ns1="http://127.0.0.1/soap/server.php?a=a&amp;b=b"
        xmlns:xsd="http://www.w3.org/2001/XMLSchema"
        xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
    SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
    <SOAP-ENV:Body>
        <ns1:test />
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>
------------