When using g_network_monitor_get_default() from another thread, it’s
possible for network-changed events to be processed after an instance of
GNetworkMonitor has been disposed, causing use-after-free problems.
Fix that by moving some of the initialisation into the GInitable.init()
chain, rather than in a main context idle callback.
This includes a unit test which probabilistically reproduces the bug
(but can’t do so deterministically due to it being a race condition).
Commit amended by Philip Withnall <withnall@endlessm.com> before
pushing.
https://bugzilla.gnome.org/show_bug.cgi?id=793727
When we are inside a sandbox, we want to use the portal
implementation, since it is the only one that has a chance
of working.
This is safe to do, since the portal implementation will
just fail initialization when loaded outside a sandbox.
The backend for this lives in xdg-desktop-portal,
and is in turn using GNetworkMonitor.
When network is not available in the sandbox, there is
no point in reporting accurately about the network
status outside the sandbox. Just return 'no connection'
in this case.
https://bugzilla.gnome.org/show_bug.cgi?id=768498
