Re: [PATCH 2/2] windowscodecs: Add support for IMILBitmapScaler interface.

[Dmitry Timoshkov]

"Vincent Povirk (they/them)"  wrote:
> +static HRESULT WINAPI
> IMILBitmapScaler_QueryInterface(IMILBitmapScaler *iface, REFIID iid,
> - void **ppv)
>
> +{
> - BitmapScaler *This = impl_from_IMILBitmapScaler(iface);
> -
> - TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);
> -
> - if (!ppv) return E_INVALIDARG;
> -
> - if (IsEqualIID(&IID_IUnknown, iid) ||
> -
>    IsEqualIID(&IID_IMILBitmapScaler, iid) ||
> -
>    IsEqualIID(&IID_IMILBitmapSource, iid))
> - {
> -
>    IUnknown_AddRef(&This->IMILBitmapScaler_iface);
>
> This violates COM rules by returning a different IUnknown pointer
> depending on the interface queried. Does native do that?

I've added more tests for IMILBitmapScaler_QueryInterface() behaviour,
and under Windows for IID_IUnknown it returns some strange interface
pointer that doesn't match other public interfaces. Then I added the
same test for IWICBitmap_QueryInterface() and it also returns some
strange interface for IID_IUnknown. So both QI implementations in Wine
have similar problems when queried for IID_IUnknown. Or do you mean
some other COM rule violation in the comment above?