Comment 5 for bug 24398

After loading a page containing a form, Firefox automatically focuses the first
input field in the tab order. It should not do this if the user has already
begun entering data into the form. Not only is the current behavior annoying,
but it is a potential security issue. I have often typed passwords into
plaintext fields because Firefox changed the field focus after a slow page load.

If the event handling isn't too messy, it should also not change the input focus
if the user is typing something in the address bar or search bar.