DSOUND: prevent assertion in mixer.c

[Felix Nawothnig]

Alex Villací­s Lasso wrote:
> wine-pthread: mixer.c:386: DSOUND_MixInBuffer: Assertion 
> `adjusted_remainder >= 0' failed.
> wine: Unhandled exception (thread 000a), starting debugger...
> WineDbg starting on pid 0x8

I guess this is preluded by some "length not a multiple of block size" 
errors? I've been experiencing those errors with the same failed 
assertion in another game and came up with a similar patch but didn't 
submit since I think this just hides another bug as it should *not* 
happen that buf_mixpos becomes greater than buflen (and this >= above 
should probably be ==) at any time.

IMHO you should at least add an ERR to that branch.

> --- wine-20050725-cvs/dlls/dsound/mixer.c	2005-06-21 04:43:29.000000000 -0500
> +++ wine-20050725-cvs-patch/dlls/dsound/mixer.c	2005-08-01 02:16:42.000000000 -0500
> @@ -491,6 +491,7 @@
>  			if (dsb->leadin && (dsb->startpos <= dsb->buf_mixpos))
>  				dsb->leadin = FALSE; /* HACK: see above */
>  		}
> +		else dsb->buf_mixpos = 0; /* %= dsb->buflen; */

And shouldn't it be "%= dsb->buflen;"? I'd think that this causes 
looping until new stuff is mixed in...

Felix