The data table is used to map objects (clients/tags) to the buttons associated
with them. This is done so that we don't have to re-create the button objects
each time this lists are updated.
The problem was that this weak-keyed table was never cleared, because the value
had a strong reference to the key (via the button's signal):
btn:connect_signal("press", function () b:emit_signal("press", o) end)
"o" is the key in the table and btn is reachable from the value. This prevented
the garbage collection of the key. Using a weak-keyed and weak-valued table
fixes this.
Signed-off-by: Uli Schlachter <psychon@znc.in>
89f05c90ca