changes to make wxWindow::FindFocus work as expected with composite controls

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29540 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/listctrl.cpp

@@ -517,6 +517,8 @@ public:
                       const wxString &name = _T("listctrlmainwindow") );
 
     virtual ~wxListMainWindow();
+    
+    wxWindow *GetMainWindowOfCompositeControl() { return GetParent(); }
 
     bool HasFlag(int flag) const { return m_parent->HasFlag(flag); }