To be consistent with the 'Clear all' button, the 'Add all' button
should only add all currently visible options to the selection.
Invisible (i.e. filtered or currently nonexistent) options should be
left as-is, selected or unselected. This is a fix for issue #4.
To be consistent with the 'Clear all' button, the 'Add all' button should only add all currently visible options to the selection. Invisible (i.e. filtered or currently nonexistent) options should be left as-is, selected or unselected. This is a fix for issue #4.