include: Avoid overflow (warning) in RGBA_MAKE.

[Henri Verbeet]

On 26 February 2017 at 15:22, Gerald Pfeifer <gerald at pfeifer.com> wrote:
> On Tue, 6 Sep 2016, Henri Verbeet wrote:
>> On 6 September 2016 at 08:41, Dmitry Timoshkov <dmitry at baikal.ru> wrote:
>>>> --- a/include/d3dtypes.h
>>>> +++ b/include/d3dtypes.h
>>>> @@ -53,7 +53,7 @@ typedef LONG D3DFIXED;
>>>>  #define RGBA_GETRED(rgb)        (((rgb) >> 16) & 0xff)
>>>>  #define RGBA_GETGREEN(rgb)      (((rgb) >> 8) & 0xff)
>>>>  #define RGBA_GETBLUE(rgb)       ((rgb) & 0xff)
>>>> -#define RGBA_MAKE(r, g, b, a)   ((D3DCOLOR) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b)))
>>>> +#define RGBA_MAKE(r, g, b, a)   ((D3DCOLOR) (((unsigned)(a) << 24) | ((r) << 16) | ((g) << 8) | (b)))
>>>
>>> This is a public header, probably you need to fix the callers of this
>>> macro instead.
>> Signed overflow is undefined, so this change is compatible. It's also
>> unlikely to be an issue in practice on any architecture we support. I
>> might have preferred something similar to D3DCOLOR_ARGB though.
>>
>> That's not to say the users of the macro don't have room for improvement.
>
> I noticed this has not been committed (nor rejected apparently).
> but after reverting it locally, I do not see the warnings that
> triggered this any longer.
>
> Did one of you commit and alternative fix?
>
Commit 060ea15ae2c1604d51d3df1460e99c7d6e6211cf should have avoided the issue.