AttributeError: 'NoneType' object has no attribute 'set_extended_away'

Versions

• OS: Arch Linux ARM
• Gajim version: 1.2.1
• GTK version: 3.24.8
• Python-nbxmpp version: 1.0.2

Steps to reproduce the problem

Reproduced on PinePhone running Arch Linux ARM with Phosh.

1. Run gajim
2. Lock the screen via the power button or just wait for it to become idle
3. Unlock again

Expected behavior

No error is shown.

Actual behavior

Gajim encountered an error:

Traceback (most recent call last):
  File "/usr/lib/python3.8/site-packages/gajim/common/client.py", line 607, in _screensaver_state_changed
    Monitor.set_extended_away(active)
  File "/usr/lib/python3.8/site-packages/gajim/common/idle.py", line 231, in set_extended_away
    self._idle_monitor.set_extended_away(state)
AttributeError: 'NoneType' object has no attribute 'set_extended_away'

Additional notes

None of the IdleMonitor implementations are applicable: 1) Mutter is not used, 2) Phosh is based on Wayland so there is no X screen saver (Xss).

The set_extended_away call happens on _idle_monitor which is not guarded in any way, resulting in the error above.

Here's a patch that helped me overcome this problem: gajim-IdleMonitor.patch