notification-area: stop warning on removal

[lukefromdc]

*Use automatic signal handling for changing icon size so this code doesn't get called when the applet is removed

[lukefromdc]

Fixes #1380

[raveit65]

I can confirm that it fixes the crashes/warnings on x11/wayland.
But what is the different between g_signal_connect and g_signal_connect_object in our case?
This fix needs to go in stable branch too, so we're lucky that no one remove this applet normally :o))
@mate-desktop/core-team
Please test, it is reproducible with stable branch.

[raveit65]

LGTM,
it fixes crashes in fedora and (only) warnings in debian.

[lukefromdc]

The difference is that g_signal_connect_object() automatically manages signal disconnection

[lukefromdc]

Just confirmed the warning also occurs on 1.26 when removing the notification area applet

[cwendling]

The difference is that g_signal_connect_object() automatically manages signal disconnection

To clarify: g_signal_connect() automatically disconnects when the object that emits the signal is destroyed (here, the settings instance). g_signal_connect_object() assumes the data argument is also a GObject, and tracks its lifetime as well.

[raveit65]

The difference is that g_signal_connect_object() automatically manages signal disconnection

To clarify: g_signal_connect() automatically disconnects when the object that emits the signal is destroyed (here, the settings instance). g_signal_connect_object() assumes the data argument is also a GObject, and tracks its lifetime as well.

So, you approve the PR?

[cwendling]

@raveit65 I couldn't test it yet, but the code looks good, yes 👍