GPtrArray API is prone to leak

[Michal Hruby]

Now that there's GObject-Introspection planned for libzg, it'd be very useful to add methods which do not consume the GPtrArray templates parameter present in many methods, as libzg is doing a lot of ref-counting magic there.

As an example, doing:
GPtrArray templates = g_ptr_array_new_with_free_func (g_object_unref);
g_ptr_array_add (g_object_ref_sink (some_event));
zeitgeist_log_find_events (zg_log, time_range, g_ptr_array_ref (templates), ...);
g_ptr_array_unref (templates);

Will result in mem leak, because the find_events call will change the free_func on the templates.

[Mikkel Kamstrup Erlandsen (kamstrup)]

I agree. The current API was developed maybe with a little to much
focus on a convenient C API. Fixing this will be an API break
nonetheless, so we can target this for the 0.4 series - at which point
we should probably also switch the VAPI to use GenericArray instead of
pointer array.