GtkSocket/GtkPlug bug in Gtk+ 2.20?

[Andy Stewart <lazycat manatee gmail com>]

Hi all,

Today, i update to Gtk+ 2.20.0, and found my GtkSocket/GtkPlug code
break in Gtk+ 2.20.0, it's works fine in Gtk+ 2.18.3:

I running GtkSocket and GtkPlug in *separate* processes.

Sometimes, i want move GtkPlug from one container (*old* GtkSocket) to
another (*new* GtkSocket) and can keep GtkPlug live.

In Gtk+ 2.18.3, i return True for GtkPlug signal "delete_event", 
then i can keep GtkPlug live when *old* GtkSocket is destroy, 
and i can use function `gtk_socket_add_id` to re-use GtkPlug when *new* GtkSocket is create.

But in Gtk+ 2.20, nothing in GtkSocket when i use "gtk_socket_add_id"
add to GtkPlug *new* GtkPlug.

I have check code of Gtk+ 2.20, but haven't found any hint.

Any idea? Or bug in Gtk+ 2.20?

  -- Andy