[openal] OpenAL fails with OSS on FreeBSD

[Chris Robinson]

On 12/01/2016 09:35 AM, Yuri wrote:
> Looking into it in the debugger.
>
> In alcOpenDevice: deviceName is passed as "OSS Default", but it gets
> overwritten within this line:
>
>>        device->Backend = V(factory,createBackend)(device,
> ALCbackend_Playback);
>
> At the moment of overwrite, the stack is:
>
> (gdb) bt
> #0  0x000000080a64ba54 in memset () from /lib/libc.so.7
> ...
>
> Debugger shows the memory is overwritten in
> ALCossBackendFactory_createBackend bu a memset inside this line:

Be careful that optimizations aren't playing tricks on the debugger. 
It's better to trace the ALCplaybackOSS_open call, and follow it through 
to see what everything is and does then. Very similar code is used to 
handle opening capture devices, which seems to work fine in your log.