[jimtabor] 33855: Prevent a crash if the list is empty and check for zero. If (List is Empty! DCE!) is called before the crash, this means we have a thread that is not finished running before shutdown. There is a proper way for handling this

Author: jimtabor
Date: Wed Jun  4 11:07:47 2008
New Revision: 33855

URL: http://svn.reactos.org/svn/reactos?rev=33855&view=rev
Log:
Prevent a crash if the list is empty and check for zero. If (List is Empty! DCE!) is
called before the crash, this means we have a thread that is not finished running before
shutdown. There is a proper way for handling this

Modified:
    trunk/reactos/subsystems/win32/win32k/ntuser/windc.c

Modified: trunk/reactos/subsystems/win32/win32k/ntuser/windc.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/nt…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/ntuser/windc.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/ntuser/windc.c [iso-8859-1] Wed Jun  4 11:07:47
2008
@@ -632,6 +632,7 @@
   KeEnterCriticalRegion();
   do
   {
+      if (!pDCE) break;
       if (pDCE->hwndCurrent == Window->hSelf)
       {
          if (!(pDCE->DCXFlags & DCX_CACHE)) /* owned or Class DCE*/
@@ -651,6 +652,7 @@
                      Window->Wnd->Style & CS_OWNDC) /* owned DCE*/
             {
                pDCE = DceFreeDCE(pDCE, FALSE);
+               if (!pDCE) break;
                Window->Dce = NULL;
                continue;
             }