Subject: bug#55645: src/print.c; print_object changes make it impossible to compare elisp code across versions

From: Lars Ingebrigtsen <[email-masked]>
Date: Thu, 26 May 2022 14:03:36 +0200

Tom Gillespie <[email-masked]> writes:

> The changes made in 637dde4aba921435f78d0de769ad74c4f3230aa6
> make it impossible to use prin1-to-string as the basis for hashing elisp
> code in a way that is independent of the emacs version.

prin1 has never guaranteed that the printed representation would be
stable across versions, so if it's worked for you, that's by accident.

> At the very least this change in behavior needs to be configurable so that
> the old behavior can be retained, preferably this change would be
> reverted entirely as it does not address the original bug (bug#23130) and
> is NOT low impact for users that actually use such functionality, whereas
> the change is completely invisible to those that do not use such functionality.

It would be possible to add something to control this details (via the
new OVERRIDES parameter), but it doesn't feel like it'd be worth it,
because, well, the representation isn't meant to be stable.

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