bug#64750: 30.0.50; [PATCH] Clicking at screen edge in X11 echoes "<nil> <mouse-1> is undefined"

[Eli Zaretskii <eliz@gnu.org>]

tags 64750 notabug
thanks

> Date: Thu, 20 Jul 2023 18:12:31 +0000
> From:  Antero Mejr via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> When clicking along the left edge of screen in a maximized emacs X11
> window, the message "<left-fringe> <mouse-1> is undefined" or
> "<nil> <mouse-1> is undefined" will appear. This can also be done with
> the right fringe, and with the top edge of the screen if the menu and
> tool bars are disabled. It can also be done using mouse events besides
> <mouse-1>, like <mouse-2>, <down-mouse-1>, or <drag-mouse-1>.

This is the correct and intended behavior, not a bug.  When the user
invokes a key sequence or a mouse gesture that is not bound to any
command, Emacs says so.

> This bug makes using programs with clickable UI elements at the edge of
> the frame annoying. The cursor tends to land in the nil or fringe areas,
> then the distracting/irrelevant message appears in the echo area when
> you attempt to click.
> 
> The attached patch globally ignores all inputs for those areas in
> fringe.el.

Thanks, but I don't think we should install this.  If the behavior you
described annoys you that much, you can always add these bindings to
your personal init files -- that's why Emacs makes it easy to
customize key bindings.  But in general, arbitrarily ignoring key
sequences just because they are not bound to commands is not TRT, IMO.