754571 - Alt key events are not triggered correctly

Status: RESOLVED DUPLICATE of bug 347010

(Core :: DOM: UI Events & Focus Handling, defect)

Description

[phi2x]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0
Build ID: 20120420145725

Steps to reproduce:

This is the scenario that causes problem :
1) Press the Alt key. 
2) While the Alt key is pressed, press another key (for example the arrow up key). 
3) Release the arrow up key. 
4) Release the Alt key. 


Actual results:

On those steps, here are the events that have been triggered by Firefox :
1) The onkeydown event is correctly triggered for the Alt key press.
2) The onkeydown event is correctly triggered for the arrow up key press.
3) The onkeyup event is correctly triggered for the arrow up key release.
4) The onkeyup event is NOT triggered for the Alt key release!


Expected results:

On step 4, I expected Firefox to trigger the onkeyup event for the Alt key release.

This is a very serious issue. This behaviour of Firefox basically forbids the use of the Alt key as a fire button in HTML5 games!

Chrome handles the Alt Key correctly in this scenario by correctly triggering the onkeyup event on step 4.