[tkreuzer] 49303: [WIN32K] Fix possible NULL pointer dereference. Spotted by Amine Khaldi.

Author: tkreuzer
Date: Wed Oct 27 12:51:32 2010
New Revision: 49303

URL: http://svn.reactos.org/svn/reactos?rev=49303&view=rev
Log:
[WIN32K]
Fix possible NULL pointer dereference. Spotted by Amine Khaldi.

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

Modified: trunk/reactos/subsystems/win32/win32k/ntuser/event.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/ntu...
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/ntuser/event.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/ntuser/event.c [iso-8859-1] Wed Oct 27 12:51:32 2010
@@ -299,17 +299,21 @@
    UserEnterExclusive();

/* Validate input */
-   if (hWnd && (hWnd != INVALID_HANDLE_VALUE) && !(Window = UserGetWindowObject(hWnd)))
-   {
-      UserLeave();
-      return;
+   if (hWnd && (hWnd != INVALID_HANDLE_VALUE))
+   {
+     Window = UserGetWindowObject(hWnd);
+     if (!Window)
+     {
+       UserLeave();
+       return;
+     }
    }

if (gpsi->dwInstalledEventHooks & GetMaskFromEvent(Event))
    {
-      UserRefObjectCo(Window, &Ref);
+      if (Window) UserRefObjectCo(Window, &Ref);
       IntNotifyWinEvent( Event, Window, idObject, idChild, WEF_SETBYWNDPTI);
-      UserDerefObjectCo(Window);
+      if (Window) UserDerefObjectCo(Window);
    }
    UserLeave();
 }