tons of fixes for wxGTK/Univ - seems to work, more or less, now

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10805 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/univ/winuniv.cpp

@@ -482,6 +482,15 @@ wxPoint wxWindow::GetClientAreaOrigin() const
 
 void wxWindow::DoGetClientSize(int *width, int *height) const
 {
+    // if it is a native window, we assume it handles the scrollbars itself
+    // too - and if it doesn't, there is not much we can do
+    if ( !m_renderer )
+    {
+        wxWindowNative::DoGetClientSize(width, height);
+
+        return;
+    }
+
     int w, h;
     wxWindowNative::DoGetClientSize(&w, &h);