return false from IsDoubleBuffered() if the first top level parent is not double...

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41814 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index e077df91af47b24c86cb1486e584194f4cfe3d47..bd7a853adf3b93f78087cf87a641d6323c8aa3e2 100644 (file)
--- 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;