fixed a crash caused by removing a message twice from the queue

reactos/subsys/win32k/ntuser

diff -u -r1.77 -r1.78
--- msgqueue.c	23 Mar 2004 22:24:27 -0000	1.77
+++ msgqueue.c	28 Mar 2004 16:21:58 -0000	1.78
@@ -16,7 +16,7 @@

  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

-/* $Id: msgqueue.c,v 1.77 2004/03/23 22:24:27 weiden Exp $

+/* $Id: msgqueue.c,v 1.78 2004/03/28 16:21:58 weiden Exp $

  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel

@@ -385,11 +385,10 @@

     {
       /* we do not hold more than one WM_MOUSEMOVE message in the queue */
       Window->MessageQueue->MouseMoveMsg->Msg = Message->Msg;

-      if(RemoveWhenFreed)

+      if(RemoveWhenFreed && FromGlobalQueue)

       {
         RemoveEntryList(&Message->ListEntry);
       }

-      ExFreePool(Message);

       *Freed = TRUE;
     }
     else

@@ -403,6 +402,10 @@

       *Freed = FALSE;
     }
     IntUnLockHardwareMessageQueue(Window->MessageQueue);

+    if(*Freed)
+    {
+      ExFreePool(Message);
+    }

     KeSetEvent(&Window->MessageQueue->NewMessages, IO_NO_INCREMENT, FALSE);
     IntReleaseWindowObject(Window);
     return(FALSE);

@@ -420,7 +423,6 @@

       {
         RemoveEntryList(&Message->ListEntry);
       }

-      ExFreePool(Message);

       *Freed = TRUE;
     }
     else

@@ -434,6 +436,10 @@

       *Freed = FALSE;
     }
     IntUnLockHardwareMessageQueue(Window->MessageQueue);

+    if(*Freed)
+    {
+      ExFreePool(Message);
+    }

     KeSetEvent(&Window->MessageQueue->NewMessages, IO_NO_INCREMENT, FALSE);
     IntReleaseWindowObject(Window);
     return(FALSE);