How to switch off autobackup for files loaded from tramp?

[Steinar Bang]

Back in September 11 2021 I added the following line to my ~/.emacs:
 (add-to-list 'backup-directory-alist (cons tramp-file-name-regexp nil))

The purpose of that setting was to turn off autobackup for files loaded
from tramp, because emacs on windows went ga-ga when I tried to modify a
file that was loaded from a server that couldn't be contacted at the
time of edit (because of firewalls).

I think the setting worked back in 2021 at whatever emacs was the
current one back then.

But the setting does not work now and looking at the
backup-directory-alist documentation, I think it is because the nil
result just tells autobackup to work as default...?

Anyway: does someone have a current, working, config that will disable
autobackup on files loaded from tramp?

Thanks!


- Steinar