I am looking for a Javascript multi-select library that allows to reuse tags. I am currently using select2, which provides everything I need (multi-select, tagging, ajax support), except for the reuse of tags. Essentially what I need is that for given the following example select:

<select class="select-multiple" name="states[]" multiple="multiple">
  <option value="1">Apple</option>
  <option value="2">Banana</option>
</select>

I want the user to be able to select Apple and then click on Apple again, and instead of it becoming deselected, it adds another Apple to the list of selected tags.

There is an open issue with this feature request for select2, but there seems to be little activity. Does anyone know how to implement this for select2 or know of another library that provides this functionality?