Source cleaning inspired by and included in patch '[ 1215450 ] cleanup: unreachable code.'

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@34548 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/mdig.cpp

@@ -344,6 +344,7 @@ void wxGenericMDIParentFrame::DoHandleMenu(wxCommandEvent &event)
                 {
 #if 1   // What's best? Delayed deleting or immediate deleting?
                     delete m_pActiveChild;
+                    m_pActiveChild = NULL;
 #else
                     ActivateNext();