mshtml: Add IHTMLXMLHttpRequest::responseXML() method implementation. (try 2)

[Nikolay Sivov]

I don't know if it's terribly important in practice or not, but it could 
be better to always initialize out pointer to NULL.

> +    hres = IXMLDOMDocument_QueryInterface(xmldoc, &IID_IObjectSafety, (void**)&safety);
> +    if(SUCCEEDED(hres)) {
> +        hres = IObjectSafety_SetInterfaceSafetyOptions(safety, NULL,
> +            INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACE_USES_SECURITY_MANAGER,
> +            INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACE_USES_SECURITY_MANAGER);
> +        IObjectSafety_Release(safety);
> +        if(FAILED(hres)) {
> +            ERR("SetInterfaceSafetyOptions(%p) failed: %08x\n", safety, hres);
> +            IXMLDOMDocument_Release(xmldoc);
> +            return hres;
> +        }
> +    } else {
> +        ERR("QueryInterface(IID_IObjectSafety) failed: %08x\n", hres);
> +        IXMLDOMDocument_Release(xmldoc);
> +        return hres;
> +    }

This looks too complicated to me, I don't think any failure here is 
critical.