bug#5923: 23.1.95; minibuffer-message discards input events

[Drew Adams]

> Actually, the problem is here in `sit-for':
>
> (let ((read (read-event nil nil seconds)))
>       (or (null read)
>         (progn
>           (if (eq overriding-terminal-local-map 
>                 universal-argument-map)
>               (setq read (cons t read)))
>           (push read unread-command-events)
>           nil))))))
> 
> Since the value of `overriding-terminal-local-map' is not
> `universal-argument-map' in my case, it fails to treat any 
> input received properly.

However, something else must be going on also, because the sit-for code is
identical for Emacs 22, and I don't see the bug in Emacs 22.