Don't try to release mutex with NULL handle. Also prevent releasing the same mutex twice.

Modified: trunk/reactos/lib/kernel32/debug/output.c

--- trunk/reactos/lib/kernel32/debug/output.c	2005-03-17 22:40:19 UTC (rev 14167)
+++ trunk/reactos/lib/kernel32/debug/output.c	2005-03-17 23:16:12 UTC (rev 14168)
@@ -456,7 +456,8 @@

    if(hDBMonDataReady) CloseHandle(hDBMonDataReady);
 
    /* leave the critical section */

-   ReleaseMutex(hDBMonMutex);

+   if(hDBMonDataReady != NULL)
+    ReleaseMutex(hDBMonMutex);

 #if 0
   }
  }