Disconnects a handler from @instance so it will not be called during
any future or currently ongoing emissions of the signal it has been
connected to. The @handler_id_ptr is then set to zero, which is never a valid handler ID value (see g_signal_connect()).
If the handler ID is 0 then this function does nothing.
A macro is also included that allows this function to be used without
pointer casts.
Disconnects a handler from @instance so it will not be called during any future or currently ongoing emissions of the signal it has been connected to. The @handler_id_ptr is then set to zero, which is never a valid handler ID value (see g_signal_connect()).
If the handler ID is 0 then this function does nothing.
A macro is also included that allows this function to be used without pointer casts.