Cloning an ECalComponent can fail, and we need to be able to
catch these failures.
Assert that cloning was successful before procceeding with
the move.
The return value is nullable, but gnome-calendar fails to check it.
Because the nullable return value is inconvenient for us, we can instead
add and use gcal_context_get_icaltimezone() to supplement the existing
gcal_context_get_timezone().
We'll also need a function to convert from GTimeZone to ICalTimezone,
gcal_timezone_to_icaltimezone().
Fixes#419
Most of these are probably paranoid, not bugs. I haven't done an
exhaustive review to see what really needs it: that would be
time-consuming and require significant familiarity with the Calendar
codebase. This was just a quick check. Anyway, I vote for paranoid
when it comes to using g_signal_connect() regardless. It's dangerous,
and there's no reason to ever leave a signal connected after the user
data object has been destroyed.
Fixes#423
This was originally discovered and fixed by Milan Crha; I'm just
forward-porting his fix to the master branch. self->clients takes
ownership of this source but we don't currently have ownership here,
leading to a double free vulnerability.
Fixes#435
While deleting the calendar, we may run into a situation
where the GcalCalendar instance is destroyed before the
GcalManager:calendar-removed signal is emitted, causing
us to emit the signal with a destroyed object.
Prevent that by increasing the ref count before emiting
the signal.
Instead of other classes needing to manually set and
unset whether a source is registered in the data model,
we can now simply call GcalCalendar.set_visible() and
have the model be updated for us.
