bug#45834: 28.0.50; Mouse events in terminal emacs

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: 45834@debbugs.gnu.org
> Date: Wed, 08 Sep 2021 11:54:01 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Meaning what? that xterm-translate-focus-in is no longer being called?
> > But you said up-thread that the handler _is_ being called.
> 
> It is called, but the event isn't translated to the [] null event any
> more, so they "leak out" into the echo area (see screenshot in message
> upstream).

It's not the echo-area that is the problem, it's the fact that "C-h k"
thinks it should describe the focus-in sequence, right?  If so, why is
that unexpected?  "C-h k" is supposed to describe the next input
event, right?  If we don't want it to describe the focus-in event, we
need to swallow it.