Comment 188 for bug 36812

Just my 0.02 cents. Why not to introduce "transaction" concept for key presses?

1. Transaction is finished when the last key is released
2. The returned result from the transaction is the sequence of keys pressed

This should solve all [Alt, Shift] problems.

Example:
  user presses Alt key
  user presses Shift key and releases it
  user presses Shift key
  user releases Alt key
  user releases Shift key

The returned sequence is [Alt, Shift, Shift]