bluez5: Fix AttributeError when registering an agent twice

[fkleon]

While I'm in there..

I noticed during some further testing that when starting bluetoothctl multiple times, with the bluez5 mock active, an AttributeError is raised instead of the expected org.bluez.Error.AlreadyExists:

$ systemctl mask bluetooth
$ systemctl stop bluetooth
$ python3 -m dbusmock --system -t bluez5 -e $SHELL

$ bluetoothctl
Waiting to connect to bluetoothd...
1720009617.228 RegisterAgent "/org/bluez/agent" ""
[SIGNAL] org.freedesktop.DBus.Mock.MethodCalled
[bluetooth]# Agent registered
[bluetooth]# quit

$ bluetoothctl
Waiting to connect to bluetoothd...
1720009619.963 RegisterAgent "/org/bluez/agent" ""
1720009619.963 RegisterAgent raised: 'DBusMockObject' object has no attribute 'agent_path'
[SIGNAL] org.freedesktop.DBus.Mock.MethodCalled
[bluetooth]# Failed to register agent: org.freedesktop.DBus.Python.AttributeError
[bluetooth]# quit

Actually, against the real bluez5 implementation, the agent would be automatically unregistered when the bluetoothctl client disconnects from DBus.. but that's a limitation of this mock/template.

[fkleon]

On centos9:

AssertionError: 'Agent registered' not found in ['Waiting to connect to bluetoothd...', 'org.freedesktop.DBus.Mock.MethodCalled', 'registered']

Not sure why this prints just registered instead of Agent registered on the old version. Based on the BlueZ source code it should be the same output.. 🤔

I guess I'll make this assertion conditional on the BlueZ version too..

[martinpitt]

Thanks @fkleon! Now that you have a commit in main the tests start automatically for you, nice 🎉