Re: [PATCH v2 1/2] jscript: implement Enumerator()

[Nikolay Sivov]

On 5/5/19 6:10 PM, Andreas Maier wrote:
> -
>    /* Try to get a IEnumVARIANT by _NewEnum */
> -
>    hres = IDispatch_Invoke(obj,
> -
>        DISPID_NEWENUM, &IID_NULL, LOCALE_NEUTRAL,
> -
>        DISPATCH_METHOD, &dispparams, &varresult,
> -
>        NULL, NULL);
> -
>    if (FAILED(hres))
> -
>    {
> -
>        ERR("Enumerator: no DISPID_NEWENUM.\n");
> -
>        hres = E_INVALIDARG;
> -
>        goto cleanuperr;
> -
>    }
> -
>    if (V_VT(&varresult) == VT_DISPATCH)
> -
>    {
> -
>        enumvar = (IEnumVARIANT*)V_DISPATCH(&varresult);
> -
>        VariantClear(&varresult);
> -
>    }
> -
>    else if (V_VT(&varresult) == VT_UNKNOWN)
> -
>    {
> -
>        hres = IUnknown_QueryInterface(V_UNKNOWN(&varresult),
> -
>            &IID_IEnumVARIANT, (void**)&enumvar);
> -
>        if (FAILED(hres))
> -
>        {
> -
>            hres = E_INVALIDARG;
> -
>            goto cleanuperr;
> -
>        }
> -
>        enumvar = (IEnumVARIANT*)V_DISPATCH(&varresult);
> -
>        VariantClear(&varresult);
> -
>    }
> -
>    else
> -
>    {
> -
>        ERR("Enumerator: NewEnum unexpected type of varresult (%d).\n", V_VT(&varresult));
> -
>        hres = E_INVALIDARG;
> -
>        goto cleanuperr;
> -
>    }

This looks too complicated, you don't need to handle VT_UNKNOWN vs 
VT_DISPATCH differently, simply QI for IEnumVARIANT when you got either 
of those. Also you immediately free varresult after assigning it, that's 
wrong; for VT_UNKNOWN case you overwrite QI result with same original 
pointer.

Additionally, 'isnull' field seems to be redundant.