[3/5] comctl32: Implement TaskDialogIndirect as a custom dialog box (try 2)

[Nikolay Sivov]

On 24.02.2015 17:37, Joachim Priesner wrote:
> Am Dienstag, 24. Februar 2015 schrieb Nikolay Sivov:
>> On 23.02.2015 15:42, Joachim Priesner wrote:
>>> +    if (IS_INTRESOURCE(text))
>>> +    {
>>> +        SetLastError(S_OK);
>>> +        LoadStringW(instance, LOWORD(text), (LPWSTR)result, 0);
>>> +        return HRESULT_FROM_WIN32(GetLastError());
>>> +    }
>>
>> You don't need SetLastError(), especially not with HRESULT value. And
>> GetLastError() should only be used when LoadStringW() fails.
>
> Thanks for the feedback, again. The rationale behind SetLastError is that the following three cases can occur:
>   1) LoadStringW succeeds, string length > 0 => return value > 0
>   2) LoadStringW succeeds, string length == 0 => return value 0
>   3) LoadStringW fails => return value 0, error code available via GetLastError.
>
> Because LastError is not modified in case 2), I have to set it to S_OK beforehand in order to distinguish between 2) and 3). Does that make sense?
>

Ok, what happens on windows if resource length is 0? If it still works 
and text is simply empty you can detect a failure another way - by 
testing returned resource pointer (I'd expect NULL if resource id was 
not found), and in that case use last error.