[gtkmm] Problem with TextBuffer::insert_at_cursor

[mike lotusland demon co uk]

(Apologies to the moderators of this list - sent two previous versions of this mail with incorrect 'From:' headers :-( )

Hi,

I get the following the second time 'insert_at_cursor' is called in the
following code. To reproduce, compile and run. Click the 'Insert Text'
button and:-

(textview:32035): Gtk-WARNING **: GtkTextMark being finalized while
still in the buffer; someone removed a reference they didn't own! Crash
impending

Segmentation fault 22:01:11

This is with CVS as of 20020916.

#include <gtkmm/main.h>
#include <gtkmm/window.h>
#include <gtkmm/box.h>
#include <gtkmm/textview.h>
#include <gtkmm/textbuffer.h>
#include <gtkmm/buttonbox.h>
#include <gtkmm/button.h>

class MyTextView : public Gtk::Window {
    Gtk::VBox vbox;
    Gtk::TextView textview;
    Glib::RefPtr<Gtk::TextBuffer> textbuffer;
    Gtk::HButtonBox buttonbox;
    Gtk::Button button;
public:
    MyTextView();
    ~MyTextView();

    void on_clicked();
};

MyTextView::MyTextView()
    :
    textbuffer(textview.get_buffer()),
    button("Inset Text")
{
    set_default_size(400, 400);
    add(vbox);
    vbox.pack_start(textview);
    vbox.pack_start(buttonbox, Gtk::PACK_SHRINK);
    buttonbox.add(button);
    button.signal_clicked().connect(SigC::slot(*this,
&MyTextView::on_clicked));
    show_all();
}

MyTextView::~MyTextView()
{
}

void MyTextView::on_clicked()
{
    textbuffer->insert_at_cursor("Some text\n");
}

int main(int argc, char *argv[])
{
    Gtk::Main main(&argc, &argv);
    MyTextView tv;
    main.run(tv);

    return 0;
}
 

I've tried trawling the source but, as I've only just started with
gtkmm, there's many things I still have to get my head around. Is there
a possibility the 'insert' TextMark is being destroyed somewhere?

Any help appreciated.

-- 
Mike.