Address field is reset to its previous value after entering invalid address

When entering non-existing address in address-field and pressing 'enter' the address field is resetted to its previous value, but the page is changed to '404 not found' page. Not very convenient to be have to retype the whole address because of a typo.

Also, because of this trying to add a bookmark of this '404 not found' page creates a bookmark with 'error 404' title but with another address.