Use this method to add an action object to the specified action group. Note that the usage of this method does not setup the accel path of the action. This may cause trouble when you try to modify the accelerator of the widget associated with the action.
To workaround this problem, either set the accel path manually using set_accel_path or add the function to the group using add_action_with_accel
See also: get_action() , remove_action()