dinput: Added a check for NULL callback in EnumDevices.

[Lucas Zawacki]

Ok, I didnt know and that changes everything. From now on I'll keep
that in mind.

Sorry for the noise.

2011/6/4 Vitaliy Margolen <wine-devel at kievinfo.com>:
> On 06/04/2011 01:32 PM, Lucas Zawacki wrote:
>>>
>>> Sometimes apps depend on the crash.  Since your change comes with a
>>> test case, it looks reasonable to me, although you might check the
>>> specific HRESULT rather than just FAILED.
>>
>> Exactly, it's not a crash on Windows. I'll resend it with an explicit
>> test.
>>
>> I was thinking of this more as "janitorial" work as opposed to fixing
>> a buggy app, maybe my comment worded it badly.
>
> AJ was explicit about such checks: unless you have an application that
> breaks because of this don't add any null checks. They needlessly slowdown
> Wine. And won't guard you against invalid pointer anyway.
>
> Vitaliy.
>