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

[Nikolay Sivov]

On 04.11.2015 15:07, Zhenbo Li wrote:
> Hi Nikolay,
>
> Thanks for your reply.
>
> 2015-11-04 16:35 GMT+08:00 Nikolay Sivov <bunglehead at gmail.com>:
>> On 04.11.2015 11:13, Zhenbo Li wrote:
>>>
>>> +    hres = IXMLDOMDocument_loadXML(xmldoc, str, &vbool);
>>> +    if(FAILED(hres)) {
>>> +        ERR("loadXML(%s) failed: %08x\n", debugstr_w(str), hres);
>>> +        IXMLDOMDocument_Release(xmldoc);
>>> +        SysFreeString(str);
>>> +        return hres;
>>> +    }
>>
>>
>> This is not how it works. loadXML() returns S_FALSE on load failure as well,
>> so you have to test strictly for S_OK, or check VARIANT_BOOL argument. You
>> can probably add a test when invalid xml stream is received to see how
>> _get_responseXML() behaves, e.g. does it return S_FALSE and a valid
>> IDispatch or does it fail and return NULL.
>>
> You're right. I checked the test case for msxml3.dll, and modified my code to:
>
>      hres = IXMLDOMDocument_loadXML(xmldoc, str, &vbool);
>      if(vbool != VARIANT_TRUE) {
>          ERR("loadXML(%s) failed: %08x\n", debugstr_w(str), hres);
>          IXMLDOMDocument_Release(xmldoc);
>          SysFreeString(str);
>          return hres;
>      }
>      SysFreeString(str);

It's safer to check both return value and flag (by the way naming it 
something less generic would be better imho); also initializing flag 
before calling loadXML() is not a bad idea as another precaution.

>
>
>> Also I don't think it's a good idea to trace xml contents.
>
> Sorry, I'm not sure the meaning of "trace xml"
> If loadXML() fails, I think the terminal output should provide verbose
> information

I disagree, it's not necessary a big deal to get garbage that's not a 
valid xml steam, and it will show up in +msxml. ERR() feels too much, 
but I'll be fine with it either way, let's see what Jacek thinks.