Protect against a driver misconfiguration

[Dmitry Timoshkov]

Hello.

Changelog:
    Dmitry Timoshkov <dmitry at codeweavers.com>
    Protect against a driver misconfiguration.

diff -u cvs/hq/wine/dlls/msacm/driver.c wine/dlls/msacm/driver.c
--- cvs/hq/wine/dlls/msacm/driver.c	Tue Jun 12 21:28:17 2001
+++ wine/dlls/msacm/driver.c	Tue Jun 12 22:30:21 2001
@@ -289,7 +289,7 @@
 MMRESULT WINAPI acmDriverOpen(PHACMDRIVER phad, HACMDRIVERID hadid, DWORD fdwOpen)
 {
     PWINE_ACMDRIVERID	padid;
-    PWINE_ACMDRIVER	pad, first_pad = NULL;
+    PWINE_ACMDRIVER	pad = NULL, first_pad = NULL;
     MMRESULT		ret;
 
     TRACE("(%p, %x, %08lu)\n", phad, hadid, fdwOpen);
@@ -332,7 +332,7 @@
 
     return MMSYSERR_NOERROR;
  gotError:
-    if (!pad->hDrvr)
+    if (pad && !pad->hDrvr)
 	HeapFree(MSACM_hHeap, 0, pad);
     return ret;
 }