bug#37769: global-set-key wrongly downcases the typed key (e.g. S-tab).

[Alan Mackenzie]

Hello, Lars.

On Thu, Oct 17, 2019 at 05:00:11 +0200, Lars Ingebrigtsen wrote:
> Alan Mackenzie <acm@muc.de> writes:

> > As a consequence, it is impossible to use M-x global-set-key to bind
> > S-tab on a tty where local-function-key-map converts S-tab to [33554441]
> > = 2^25 + 9.

> [...]

> > This fix should also be safe, since it is only in the interactive spec
> > part of the function, and thus can only affect interactive use.

> > Any objections to me installing this fix on the master branch?

> Hm...  but you can't use S-tab on a tty, surely?

_I_ can, because I've set up my (Linux) tty's keyboard and Emacs to do
this.  (This according to a scheme written by Kalle Niemitalo about
twenty years ago.)

> So we're offering to interactively bind a key that can't be used (after
> this change)?  Or am I misunderstanding something?

The same problem applies to any unused keybinding involving an upper case
letter.   For example, if you tried to bind C-M-S-a on a tty with M-x
global-set-key, that function would bind C-M-a instead.  This is not
good.

I can't see see any circumstances where a user would want such a
keybinding to be downcased.  Nearly all of the time, she will have
expressly pressed the shift key.

> -- 
> (domestic pets only, the antidote for overdose, milk.)
>    bloggy blog: http://lars.ingebrigtsen.no

-- 
Alan Mackenzie (Nuremberg, Germany).