User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b5) Gecko/20050926 Firefox/1.4 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b5) Gecko/20050926 Firefox/1.4 The change event is firing when changing and undoing a selection of a non-drop-down select element, within the same mouse drag action. Reproducible: Always Steps to Reproduce: 1. Mousedown on the first option of the first select 2. Move the cursor down over the second option 3. Move the cursor back up over the first option 4. Mouseup over the first option Actual Results: Change event is fired Expected Results: Change event is not fired The source of this may be here: http://lxr.mozilla.org/mozilla1.8/source/layout/forms/nsListControlFrame.cpp#2557 as mChangesSinceDragStart gets set to PR_TRUE during the mouse drag action, but with this particular select situation a change event should only be dispatched if the selected options on mouseup are different from the selected options on mousedown.

Could you give a testcase? I failed to make one that shows the problem.

Thanks! Stupid of me, I was trying a drop-down select, while you specifically said it was a non-drop-down select that has the bug. This bug is also noticable in Mozilla1.7 The lxr link you gave points to changes made by Robert in bug 207637. CC-ing him.