unexpected _child(lose) for a detached session from _start

Hi POE fellows,

I'm in the process of rewriting the backend of my POE::Component::Schedule
to make the backend session independent of others session in the system. The
point is that session is just backend stuff, so it should not fire _child
events to the session from which the API may have been called. Also, the
schedule session is a singleton that may be used by multiple session, so it
has no reason for being attached to a particular session.
To achieve that, I'm calling POE::Kernel->detach_myself in the _start
handler of the session. POE does'nt fire _child(create) as I expected.
However I also found out that POE still fires _child(lose).

My opinion is that POE should not fire a _child(lose) event if the session
is detached from its parent in the _start handler as a 'lose' without
'create'/'gain' is inconsistent.
Also it would be better if 'detach => 1' was an argument to
POE::Session->create(): it would make the 'not attached' particularity of
this session more explicit for people reading the code.

Here is a test case that shows the current flawed behavior (tested with POE
1.006, POE 1.280):

use strict;
use warnings;

use Test::More tests => 7;
use POE;

my $_child_fired = 0;

POE::Session->create(
    inline_states => {
        _start => sub {
            $_[KERNEL]->alias_set('First');
            pass "_start First";
            POE::Session->create(
                inline_states => {
                    _start => sub {
                        $_[KERNEL]->alias_set('Second');
                        pass "_start Second";
                    },
                },
            );
            POE::Session->create(
                inline_states => {
                    _start => sub {
                        $_[KERNEL]->alias_set('Detached');
                        pass "_start Detached";
                        diag "Detaching session 'Detached' from its parent";
                        $_[KERNEL]->detach_myself;
                    },
                },
            );
        },
        _child => sub {
            $_child_fired++;
            ok($_[KERNEL]->alias_list($_[ARG1]) ne 'Detached',
                "$_[STATE]($_[ARG0]) fired for "
                  .$_[KERNEL]->alias_list($_[ARG1]->ID));
        },
    },
);

POE::Kernel->run();

pass "_child not fired for session detached in _start" unless $_child_fired
!= 2;
pass "Stopped";


Olivier Mengué
http://o.mengue.free.fr/