[v2] comctl32/taskdialog: Implement nDefaultButton and add tests

[Nikolay Sivov]

On 05.11.2017 18:46, Fabian Maurer wrote:
> I reworked my patch according to your suggestions.
> 
>>>> We already iterate over custom buttons and check every common button
>>>> flag before this point, so it shouldn't be necessary to have another loop.
>>>
>>> I'm open to suggestion, but how would you do that?
>>>
>>> We could add three checks each time before taskdialog_init_button is 
> called, 
>>> or alternatively one check in taskdialog_init_button. Like giving it a 
> pointer 
>>> to default_button, and checking if the id equal the taskdialog default 
> button.
>>> But I find my current solution to be cleaner to be honest, what's your 
>>> suggestion?
>> Yes, something like that. taskdialog_init_button() has all the info to
>> do that.
> 
> In the beginning I wanted to have default_button be -1 if no button was found 
> yet, but as the tests show this is impossible since windows accepts a negative 
> ID. Now we have to pass 2 pointers around..
> Your thoughts on that? I find that the second loop makes things a lot cleaner.

I sent another version that doesn't touch helper interface and uses
single variable to mark default button, with otherwise unchanged logic
and tests.

> 
> Regards,
> Fabian Maurer
>