To reproduce:

1. Click on the input field, and enter some text
2. Click on the "nothing" button

On Firefox 4b8, the change and blur events are not dispatched.
(When the change/blur listener are called, alerts are shown.)
It is called on Firefox 3.6, Safari 5, and just any other browser.

Note this is related by not different than Bug 577316.
The issue here is not that the button doesn't get the focus,
but that the change event is not dispatched to input field.

Also related, at the UX level, on Safari 5 the input looses the
focus when clicking on the button, even if the button doesn't
acquire the focus. This is not the case on Firefox 4b8. As it