Re: [Pan-users] Pan bug 712539 and 757672

[Petr Kovar]

On Thu, 10 Mar 2016 00:00:05 +0100
Rhialto <address@hidden> wrote:

> On Wed 09 Mar 2016 at 22:42:26 +0100, Petr Kovar wrote:
> > Thanks for all the info, Olaf! So this patch will do?
> > 
> > --- /tmp/ezzIwP_body-pane.cc
> > +++ /tmp/pan2/pan/gui/body-pane.cc
> > @@ -1637,7 +1637,6 @@
> >  
> >    {
> >      gtk_container_remove (GTK_CONTAINER (_att_frame), _att_toolbar);
> > -    if (G_IS_OBJECT(_att_toolbar)) g_object_unref(_att_toolbar);
> >      (void)create_attachments_toolbar(_att_frame);
> >    }
> >  
> 
> Yes, that should do it. Or even better would be
> 
> -    if (G_IS_OBJECT(_att_toolbar)) g_object_unref(_att_toolbar);
> +    _att_toolbar = NULL;
> 
> that would make it clearer if _att_toolbar is accidentally used later
> on.

Cool, I've just pushed the patch to master. Thanks again!

> I have double-checked it, and I am basing my reasoning on this documentation:
> https://developer.gnome.org/gtk2/stable/GtkContainer.html
> The description for gtk_container_remove() mentions refcounts, but
> gtk_container_add() doesn't.  gtk_table_new()
> doesn't mention refcounts either; I would have liked some reference to
> https://developer.gnome.org/gobject/unstable/gobject-The-Base-Object-Type.html#floating-ref
> or
> https://developer.gnome.org/gobject/unstable/gobject-memory.html#gobject-destruction-table
> (which took some clicking around to find).
> It seems that the general pattern is that gtk_table_new() would create a
> "floating reference" and gtk_container_add() would turn that into a
> normal reference. gtk_container_remove() would finally remove it, and
> because it is now zero the object gets deleted.
> 
> (An alternative approach could be to add a refcount to _att_toolbar
> just after creating it, but I don't see any particular advantage to that
> at the moment.)
> 
> Shall I look at some more of these, later on? (After the currently
> pending changes; I don't want to mix too many things at the same time.)

That'd be great, really. Anything that improves the Pan code base is
much needed at this point. :)

pk