From 786eaea3f022217e2361bd7331b0280bf9f9a4a2 Mon Sep 17 00:00:00 2001
From: David Welch <welch@cwcom.net>
Date: Fri, 1 Aug 2003 20:24:54 +0000
Subject: [PATCH] - Check the validity of the window handle before calling
 checking for a desktop in NtUserGetAncestor.

svn path=/trunk/; revision=5372
---
 reactos/subsys/win32k/include/window.h  |  2 +-
 reactos/subsys/win32k/ntuser/callback.c |  7 ++--
 reactos/subsys/win32k/ntuser/window.c   | 45 ++++++++++---------------
 3 files changed, 23 insertions(+), 31 deletions(-)

diff --git a/reactos/subsys/win32k/include/window.h b/reactos/subsys/win32k/include/window.h
index a1556462967..be5a2ecfcef 100644
--- a/reactos/subsys/win32k/include/window.h
+++ b/reactos/subsys/win32k/include/window.h
@@ -102,7 +102,7 @@ VOID     FASTCALL W32kReleaseWindowObject (PWINDOW_OBJECT Window);
 HWND     STDCALL  W32kCreateDesktopWindow (PWINSTATION_OBJECT WindowStation,
 			PWNDCLASS_OBJECT DesktopClass,
 			ULONG Width, ULONG Height);
-BOOL     FASTCALL W32kIsDesktopWindow (HWND hWnd);
+BOOL     FASTCALL W32kIsDesktopWindow (PWINDOW_OBJECT Window);
 HWND     FASTCALL W32kGetActiveWindow (VOID);
 BOOL     FASTCALL W32kIsWindowVisible (HWND Wnd);
 BOOL     FASTCALL W32kIsChildWindow (HWND Parent, HWND Child);
diff --git a/reactos/subsys/win32k/ntuser/callback.c b/reactos/subsys/win32k/ntuser/callback.c
index fa595315a75..b83cc01fdbf 100644
--- a/reactos/subsys/win32k/ntuser/callback.c
+++ b/reactos/subsys/win32k/ntuser/callback.c
@@ -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: callback.c,v 1.10 2003/06/05 03:55:36 mdill Exp $
+/* $Id: callback.c,v 1.11 2003/08/01 20:24:54 dwelch Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -176,11 +176,14 @@ W32kCallWindowProc(WNDPROC Proc,
   NTSTATUS Status;
   PVOID ResultPointer;
   ULONG ResultLength;
+  PWINDOW_OBJECT WindowObject = W32kGetWindowObject(Wnd);
 
-  if (W32kIsDesktopWindow(Wnd))
+  if (W32kIsDesktopWindow(WindowObject))
     {
+      W32kReleaseWindowObject(WindowObject);
       return(W32kDesktopWindowProc(Wnd, Message, wParam, lParam));
     }
+  W32kReleaseWindowObject(WindowObject);
 
   Arguments.Proc = Proc;
   Arguments.Wnd = Wnd;
diff --git a/reactos/subsys/win32k/ntuser/window.c b/reactos/subsys/win32k/ntuser/window.c
index 1209f218caa..afd4310a42c 100644
--- a/reactos/subsys/win32k/ntuser/window.c
+++ b/reactos/subsys/win32k/ntuser/window.c
@@ -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: window.c,v 1.73 2003/08/01 14:44:03 dwelch Exp $
+/* $Id: window.c,v 1.74 2003/08/01 20:24:54 dwelch Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -69,52 +69,44 @@ static LIST_ENTRY RegisteredMessageListHead;
 HWND STDCALL
 NtUserGetAncestor(HWND hWnd, UINT Flags)
 {
-  if (W32kIsDesktopWindow(hWnd))
+  PWINDOW_OBJECT WindowObject;
+  WindowObject = W32kGetWindowObject(hWnd);
+  if (WindowObject == NULL)
+    {
+      return(NULL);
+    }
+  if (W32kIsDesktopWindow(WindowObject))
     {
       return(NULL);
     }
   if (Flags & GA_PARENT)
-    {
-      PWINDOW_OBJECT Window;
+    {      
       HWND hParent;
 
-      Window = W32kGetWindowObject(hWnd);
-      if (Window == NULL)
+      if (WindowObject->Parent == NULL)
 	{
-	  return(NULL);
-	}     
-
-      if (Window->Parent == NULL)
-	{
-	  W32kReleaseWindowObject(Window);
+	  W32kReleaseWindowObject(WindowObject);
 	}
 
-      hParent = Window->Parent->Self;
+      hParent = WindowObject->Parent->Self;
 
-      W32kReleaseWindowObject(Window);
+      W32kReleaseWindowObject(WindowObject);
 
       return(hParent);
     }
   else if (Flags & GA_ROOT)
   {
-	  PWINDOW_OBJECT Window;
 	  PWINDOW_OBJECT pChainEnumerator;
 	  HWND hRoot;
 
-	  Window = W32kGetWindowObject(hWnd);
-	  if(Window == NULL)
-	  {
-		  return(NULL);
-	  }
-
-	  pChainEnumerator = Window;
-	  while(!W32kIsDesktopWindow(pChainEnumerator->Parent->Self))
+	  pChainEnumerator = WindowObject;
+	  while(!W32kIsDesktopWindow(pChainEnumerator->Parent))
 	  {
 	    pChainEnumerator = pChainEnumerator->Parent;
 	  }
 
 	  hRoot = pChainEnumerator->Self;
-	  W32kReleaseWindowObject(Window);
+	  W32kReleaseWindowObject(WindowObject);
 
 	  return(hRoot);
   }	  
@@ -228,13 +220,10 @@ W32kIsWindowVisible(HWND Wnd)
 }
 
 BOOL FASTCALL
-W32kIsDesktopWindow(HWND hWnd)
+W32kIsDesktopWindow(PWINDOW_OBJECT WindowObject)
 {
-  PWINDOW_OBJECT WindowObject;
   BOOL IsDesktop;
-  WindowObject = W32kGetWindowObject(hWnd);
   IsDesktop = WindowObject->Parent == NULL;
-  W32kReleaseWindowObject(WindowObject);
   return(IsDesktop);
 }