Re: small bug in mshtml component

[Jacek Caban]

Hi Andrey,

Andrey Turkin wrote:
> Hi,
>
> Just found a bug in mshtml component get_body method implementation. If
> one call it right after creation of CLSID_HTMLDocument instance, then it
> would return success and pass NULL as body object. Native would return
> "empty" body object instead. Native atl.dll library uses this behavior
> and because of this segfaults.
> I'm not acquainted with mshtml code enough to provide bug fix or even
> test patch (I mean "proper" test). Here is quick-n-dirty test instead:
>
> void test_for_body(void)
> {
>     HRESULT hr;
>     IHTMLDocument *doc;
>     IHTMLDocument2 *doc2;
>     IPersistStreamInit *psi;
>     IHTMLElement *body;
> hr = CoCreateInstance(&CLSID_HTMLDocument, NULL, CLSCTX_SERVER,
>
> &IID_IHTMLDocument, (void**)&doc);
>     ok( SUCCEEDED(hr), "CoCreateInstance failed:%08x\n", hr);
>     hr = IHTMLDocument_QueryInterface(doc, &IID_IPersistStreamInit,
> (void**)&psi);
>     ok( SUCCEEDED(hr), "QI PSI failed %08x\n", hr );
>     IPersistStreamInit_InitNew( psi );
>     IPersistStreamInit_Release( psi );
>     hr = IHTMLDocument_QueryInterface(doc, &IID_IHTMLDocument2,
> (void**)&doc2);
>     IHTMLDocument_Release( doc );
>     ok( SUCCEEDED(hr), "QI HD2 failed %08x\n", hr );
>     hr = IHTMLDocument2_get_body( doc2, &body);
>     IHTMLDocument2_Release( doc2 );
>     ok( SUCCEEDED(hr), "get_body failed %08x\n", hr );
>     ok( body != NULL, "get_body returned NULL\n" );
>     if ( body != NULL )
>    IHTMLElement_Release( body );
> }
>
> I hope a man with good mshtml knowledge would easily turn this test into
> neat small test in few minutes.

Thanks for your work on this. Are you sure you have wine_gecko
installed? I'm asking because your test works for me. The correct
behavior requires quite much work as it depends on a correct
loading routine, but I'd expect the currentimplementation to be
enough in your case. The background of this problem is:

- current implementation
get_body calls Gecko's GetDocument that loads about:blank
page in case no page is loaded and returns its body.

- correct implementation
get_body return S_OK and NULL if no page is loaded. However
IniNew call initializes document so get_body will return a valid
body object.

The loading routine is the main problem with current MSHTML,
but I'd expect it to be enough for your case.

Thanks,
    Jacek