As per http://www.w3.org/TR/html4/interact/forms.html#adef-disabled if you use "disabled" in a multi select nothing happens. // example <form name="form"> <select multiple="multiple"> <option value="1">my value 1</option> <option value="2" disabled>you should not be able to select this</option> <option value="3">my value 3</option> </select> </form>
Confirmed with 2.0.1 and ToT.
Created attachment 4895 [details] Handle disabled option elements
<rdar://problem/3266722> <option> elements marked disabled are not disabled in the menu or list for the <select> (4340)
Comment on attachment 4895 [details] Handle disabled option elements looks good, r=me
*** Bug 8979 has been marked as a duplicate of this bug. ***