Bug in dbus daemon signal routing

[Nick Jones]

We have experienced this strange behaviour:
- Server registers a method and waits for clients
  The method records the name of the last caller and will periodically
  send a signal ('Wakeup') directed only to that name owner, if a
  new client calls the method, the Wakeup signal will go to the new
  client
- Client with name :1 connects to dbus and invokes the method,
  connects to Wakeup signal
- Server sends Wakeup signal to :1
- Client :1 receives Wakeup signal directed to :1
- Previous two steps repeated periodically
- Client with name :2 connects to dbus and invokes the method,
  connects to Wakeup signal
- Server sends Wakeup signal to :2
- Client :2 receives Wakeup signal directed to :2
- Client :1 receives Wakeup signal directed to :2 - unexpected
- Previous three steps repeated periodically
- Client :2 disconnects
- Server sends Wakeup signal to :2, (true... it should detect nameowner
  change from :2 to "", but following behaviour observed)
- Client :1 no longer receives signals directed to :2

This implies that dbus daemon is correctly handling disconnection of a
nameowner and not broadcasting more signals directed to that nameowner,
but in the earlier case where a signal changes its target, dbus is not
respecting the value of the new target nameid.

Or it implies we have used the dbus api incorrectly or made wrong
assumptions about the behaviour of the dbus daemon.

Tested in environments:
Rhel6:
  dbus-1.4.6-3.nb5.0.4.x86_64 (upgraded from standard v1.2.24), 
  perl-Net-DBus-0.33.6-8.nb5.0.2.x86_64 (from EPEL6)

Fedora16:
  dbus-1.4.10-3.fc16.x86_64,
  perl-Net-DBus-0.33.6-10.fc16.x86_64

Tests scripts are attached.

Thanks

-- 
Nick Jones                              nick.jones at network-box.com
Senior Manager                          Core Development Team

Network Box Corporation Ltd
16th Floor, Metro Loft,
38 Kwai Hei Street,                     Tel: +852 2736 2083
Kwai Chung, Kowloon,                    Fax: +852 2736 2778
Hong Kong S.A.R.                        www.network-box.com
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