On Tue, Nov 26, 2019 at 8:36 PM Eli Zaretskii <eliz@gnu.org> wrote:

> We previously signaled user-error in situations where we couldn't
> continue at all.  Your addition is in a situation where nothing
> particularly bad happened, so from the POV of a caller, we are now
> signaling a user-error gratuitously.  I'm bothered only by the change
> whereby we signal a user-error with the purpose of attracting the
> user's attention, not because we cannot continue.

I don't really see much difference.

In the two cases that already signal user-error, "continuing" would mean
doing nothing; there would be no other bad consequence. In the case I've
changed, continuing means the same: doing nothing. In all three cases,
signaling, instead of continuing, is purely to attract the user's attention.

In my opinion, such code should call switch-to-(prev|next)-buffer instead.

Anyway, there's no point in arguing this; if you feel strongly that the
last case should depend on called-interactively-p, I'll change it. But I
think we should instead leave it as it is and educate code writers to use
the documented calls instead of the user-level commands.