From c719013fd40f1d9f0cd1eff5be177da9a743d5c7 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Mon, 9 Oct 2006 16:57:06 +0000
Subject: [PATCH] return false from IsDoubleBuffered() if the first top level
 parent is not double buffered

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41814 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 src/msw/window.cpp | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index e077df91af..bd7a853adf 100644
--- a/src/msw/window.cpp
+++ b/src/msw/window.cpp
@@ -3952,13 +3952,12 @@ bool wxWindowMSW::HandlePower(WXWPARAM WXUNUSED_IN_WINCE(wParam),
 
 bool wxWindowMSW::IsDoubleBuffered() const
 {
-    const wxWindow* wnd = this;
-
-    while ( wnd )
+    for ( const wxWindow *wnd = this;
+          wnd && !wnd->IsTopLevel(); wnd =
+          wnd->GetParent() )
     {
-        if ( ::GetWindowLong((HWND)wnd->GetHWND(), GWL_EXSTYLE) & WS_EX_COMPOSITED )
+        if ( ::GetWindowLong(GetHwndOf(wnd), GWL_EXSTYLE) & WS_EX_COMPOSITED )
             return true;
-        wnd = wnd->GetParent();
     }
 
     return false;