ddraw.h structure alignment

[Stefan Dösinger]

Am 11.10.2009 um 14:42 schrieb Markus Stockhausen:

> Am Sonntag, den 11.10.2009, 13:18 +0200 schrieb Markus Stockhausen:
>> Then I'm somehow in trouble. How can one explain the following
>> error: Application calls IDirectDraw GetDeviceIdentifier of
>> DDRAW7 but only reserves memory with sizeof(DDEVICEIDENTIFIER)
>> instead of sizeof(DDEVICEIDENTIFIER2) bytes. Wine returns the
>> required structure but with the contents of dwWHQLLevel
>> stack contents are overwritten.
>>
>> Markus
>>
>
> Source of error was found. DDEVICEIDENTIFIER2 is aligned to 8 bytes  
> and
> therefore 4 bytes too large (at least on my 64 bit Linux). Should a
> patch include a pragma pack handling in the ddraw.h file itself or is
> there any other location where one can fix that?
Does a pragma pack fix the issue? If yes, then that's probably the  
correct fix.

Its probably worth writing a test that allocates e.g. a char data[64],  
then passes this to GetDeviceIdentifier, fill it with non-zero data,  
and check how much is overwritten.

Otoh I find it strange that the struct is aligned to 8 bytes. Are you  
running wine in 64 bit? Or do you have some other compiler flags that  
make the compiler use 8 byte alignment?