Gtk::TreeSelection problem (redux)

[Phil Wolff <adiabat centurylink net>]

Please ignore my previous and incomplete post.


    int n = m_refFileSelection->count_selected_rows ();
    if ( n == 1 ) {
        Gtk::TreeIter iter = m_refFileSelection->get_selected ();
        if ( iter )  {
            m_refFileSelection->unselect ( iter );
        }
    }

and

    int n = m_refFileSelection->count_selected_rows ();
    if ( n != 0 ) {
        m_refFileSelection->unselect_all ();
    }

Both of these code snippets generate the following two error messages 
when the if-test is satisfied:

    Gtk-CRITICAL **: gtk_tree_store_get_value: assertion 'VALID_ITER 
(iter, tree_store)' failed
    GLib-GObject-CRITICAL **: g_value_get_string: assertion 
'G_VALUE_HOLDS_STRING (value)' failed

Is this reasonable?