Patrick Ohly authored Nov 23, 2012 and Philip Withnall committed Nov 24, 2012

Properties with delayed loading always went through an update check
each time the property was read. This slowed down reading
unnecessarily, because constructing the value is costly and necessary
updates are already dealt with via notifications.

Fixed by introducing a new parameter "force_update" which is true
by default (= same behavior as before) and false when used inside
get().

Closes: https://bugzilla.gnome.org/show_bug.cgi?id=688834