Hi Anton,
On 02/12/2018 10:36 PM, Anton Romanov wrote:
+HRESULT WINAPI WMPControls_QueryInterface(IWMPControls *iface, REFIID riid, void **ppv) +{
- if(IsEqualGUID(riid, &IID_IDispatch)) {
*ppv = iface;- }else if(IsEqualGUID(riid, &IID_IWMPControls)) {
*ppv = iface;- }else {
WARN("Unsupported interface (%s)\n", wine_dbgstr_guid(riid));*ppv = NULL;return E_NOINTERFACE;- }
- IUnknown_AddRef((IUnknown*)*ppv);
- return S_OK;
+}
This breaks COM rules: if iface1->QI(IID_iface2) returns iface2, then iface2->QI(IID_iface1) should work as well. I tried your tests and it seems that MS violates this rule as well, but in a different way than you do. What's even more important, interface returned by QI is not the same as returned by get_controls(). get_controls() should return a different object. I guess that your application needs get_controls() working, not QI(IID_IWMPControls)? I'd suggest to implement IWMPControls in a separated object (I guess that's what you really want to fix) and ignore the fact that it's also returned by QI() to avoid messing with broken behaviour.
Also, please use consistent implementation order: IUnknown functions first followed by other parent's interfaces (like IDispatch), followed by actual interface implementation.
Thanks, Jacek