Re: What's happened to M-<tab> `completion-at-point'?

[Eli Zaretskii]

> Date: Wed, 4 May 2022 18:13:30 +0000
> Cc: emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> > >     [backtab] is undefined
> 
> > And what does "C-h l" show after that?
> 
> If I first press ESC TAB and C-h l, followed by C-M-i and C-h l, I get
> this:
> 
>  ESC TAB ;; nil
>  C-h l   ;; view-lossage
>  ESC TAB ;; nil
>  C-h l   ;; view-lossage

Sp who is converting this to <backtab>?

> I think I've found the problem.  A new version of ncurses was
> installed on my machine on 2022-05-01.  It contains a version of
> terminfo, specifically /etc/terminfo/l/linux.
> 
> The new version is ncurses-6.3_p20211106.  The old version was
> ncurses-6.2_p20210619.
> 
> So, possibly we need to amend Emacs (? src/term.c) to work properly on
> this version of the Linux console.

Amend how?  I still don't understand where did <backtab> come from.
If you do understand, can you describe that?