bug#41466: 26.1; compose key no longer works

[Stefan Kangas <stefan@marxist.se>]

mousebot <mousebot@riseup.net> writes:

> im running debian gnu/linux with xfce. i don't use any alternative input
> method frameworks (so i think that means i use xim?).
>
> my compose key no longer works. i have i bound to 'print screen' in
> X. it works in all applications except emacs. it was also working in
> emacs but then stopped recently.  when i hit print screen, i receive
> the message '<Multi_key> is undefined'
>
> it doesn't work if i run 'emacs -Q'. it doesn't work if i run 'env -u XMODIFIERS emacs'.
>
> i describe what else i have tried here, based on other ppl who have had similar problems in the past:
> https://emacs.stackexchange.com/questions/58668/compose-key-stopped-working?noredirect=1#comment91514_58668.
>
> i'm not sure what caused the problem, as i don't use the key non-stop. i'm a non-technical user of emacs, so i won't speculate on what's wrong. i wondered if it cd be because the way i set my compose key. i tried setting it in different dot files and also leaving it to the xfce gui keyboard settings to no effect. it is also set in /etc/default/keyboard but i did not touch that. is it possible that changing the way it is set could impact emacs behaviour?

Could you please show us step by step how to reproduce this bug,
starting from the exact command you use to bind print screen to compose
and followed by "emacs -Q"?  Which keys do you press, and what is the
result you expect?

Could you try the `xev` program in an xterm window and tell us what it
shows when you press that key?

> In GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
>  of 2019-09-23, modified by Debian built on x86-grnet-01
> Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
> System Description:	Debian GNU/Linux 10 (buster)

Can you reproduce this also on Emacs 27.1?

Thanks in advance.