Cancel session shutdown

[Xavier Claessens <xclaesse gmail com>]

Hi,

I'm implementing D-Bus support in xchat/xchat-gnome and here is
something I want to do:

When the X session is closing and xchat has DCC transfers running I want
to be notified and in some cases cancel the session shutdown.

I'm sure that's some kind of thing possible with some D-Bus
methods/signals but I can't find anywhere documentation about that...
Can someone point me the good way for such things ?

Thanks,
Xavier Claessens.