Subject: bug#32252: [PATCH] %o and %x now format signed numbers

From: Drew Adams <[email-masked]>
Date: Mon, 23 Jul 2018 18:16:52 -0700 (PDT)

> Although it is indeed an incompatible change, I surveyed the existing
> Emacs source code and couldn't find anything that the change would
> break.

Inadequate.  Never wholly irrelevant, but certainly not
sufficient.  You surveyed something mostly irrelevant.

Emacs is about users.  Users use Elisp.  Lisp code delivered
with Emacs is not the same as the set of existing Emacs Lisp
code. Far, far from it.  This is a classic mistake.

> Almost all uses ... would not change.

What should be done, usually (not always):

1. Keep the default behavior - at least for a while
   (typically quite a while).

2. Ask users.  Take a poll - beyond this list.

What should not be done, usually:

* Just do what you feel like - make the default behavior
  whatever you like.

(Note: I don't have a horse in this race.  I don't care
what the default behavior is in this case, other than,
other things being equal it should be kept as is, as
that usually perturbs users least.)