[patch] segv on use-after-free in dsound/buffer.c

[Yuriy Kaminskiy]

Hello!
   One of games rarely crashed with segv in line 86 of dsound/buffer.c:
85:      IDirectSoundBuffer_Release((LPDIRECTSOUNDBUFFER)This->dsb);
86:      This->dsb->notify = NULL;
   (sorry, I failed to save actual backtrace at the time). This looks 
like typical assign-after-free bug. I've applied attached patch 
(wine-1.1.7, now on 1.1.19), no crashes so far (btw, similar 
*Secodary*Release method down in code uses proper order - 
assign-NULL-then-release).
--- wine-1.1.7/dlls/dsound/buffer.c.orig	2009-03-14 15:28:10.000000000 +0300
+++ wine-1.1.7/dlls/dsound/buffer.c	2009-04-23 19:50:42.000000000 +0400
@@ -82,8 +82,8 @@  static ULONG WINAPI IDirectSoundNotifyImpl_Release(
     TRACE("(%p) ref was %d\n", This, ref + 1);
 
     if (!ref) {
-        IDirectSoundBuffer_Release((LPDIRECTSOUNDBUFFER)This->dsb);
         This->dsb->notify = NULL;
+        IDirectSoundBuffer_Release((LPDIRECTSOUNDBUFFER)This->dsb);
         HeapFree(GetProcessHeap(), 0, This);
         TRACE("(%p) released\n", This);
     }