Re: [PATCH v15 0/2] MR3391: mshtml: implement window.MutationObserver with MutationObserver stub

[Gabriel Ivăncescu (＠insn)]

Gabriel Ivăncescu (@insn) commented about dlls/mshtml/mutation.c:
> +};
> -
>
> +HRESULT mutation_observer_ctor_value(DispatchEx *dispex, LCID lcid,
> -
>    WORD flags, DISPPARAMS *params, VARIANT *res, EXCEPINFO *ei,
> -
>    IServiceProvider *caller)
>
> +{
> - struct mutation_observer_ctor *This = mutation_observer_ctor_from_DispatchEx(dispex);
> - VARIANT *callback;
> - IWineMSHTMLMutationObserver *mutation_observer;
> - HRESULT hres;
> - int argc = params->cArgs - params->cNamedArgs;
> -
> - TRACE("(%p)->(%lx %x %p %p %p %p)\n", This, lcid, flags, params, res, ei, caller);
> -
> - if (argc < 1)
> -
>    return E_UNEXPECTED;

Sorry, I missed this earlier. You need to check `flags` before argc (also please remove `cNamedArgs` and just check `params->cArgs` directly instead of using argc variable, as I said, we don't handle named args anyway).

Something like this should work:

```c
    switch (flags) {
    case DISPATCH_METHOD | DISPATCH_PROPERTYGET:
        if (!res)
            return E_INVALIDARG;
        /* fall through */
    case DISPATCH_METHOD:
    case DISPATCH_CONSTRUCT:
        break;
    default:
        FIXME("flags %x not supported\n", flags);
        return E_NOTIMPL;
    }
```