[Bug 29359] DSOUND_BufPtrDiff: Assertion `ptr1 < buflen' failed.

http://bugs.winehq.org/show_bug.cgi?id=29359

--- Comment #11 from Andrew Eikum  2011-12-27 08:09:24 CST ---
This is caused by bad buffer wrap-around logic. This little diff should fix it.
We're working on other changes to dsound, so I'll see what happens with those
changes before pushing this one out.

diff --git a/dlls/dsound/mixer.c b/dlls/dsound/mixer.c
index e61c93d..62c1b9e 100644
--- a/dlls/dsound/mixer.c
+++ b/dlls/dsound/mixer.c
@@ -573,8 +573,7 @@ static DWORD DSOUND_MixInBuffer(IDirectSoundBufferImpl
*dsb, DWORD writepos, DWO

/* increase mix position */
        dsb->primary_mixpos += len;
-       if (dsb->primary_mixpos >= dsb->device->buflen)
-               dsb->primary_mixpos -= dsb->device->buflen;
+       dsb->primary_mixpos %= dsb->device->buflen;
        return len;
 }