Clicking on a listbox element that was selected from JS or via an HTML "selected" attribute now erroneously causes an onchange event to be dispatched.
Created attachment 13105 [details]
This is an extended fast/forms/listbox-onchange.html test.
It also shows that setting value attribute of a multiple select listbox works incorrectly, not sure whether this is a regression, too.
Created attachment 13121 [details]
A bigger test case.
Committed revision 20259.