Re: [PATCH] When deleting in bookmark menu, prompt for confirmation.

[Karl Fogel]

On 03 May 2021, Stefan Kangas wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
>
> > > I don't see how backwards-compatibility is relevant here, but 
> > > perhaps
> > > you could provide more specifics.
> >
> > We are now asking for confirmation where previously no question 
> > was
> > asked, or am I missing something?
>
> My point is that backwards compatibility is not necessarily the 
> most
> important consideration in this case, and that such a stance 
> would at
> least need some elaborating.
>
> AFAICT, we routinely make "backward incompatible" changes where 
> we see
> a need for it.  (But of course we do them with care and 
> consideration.)
>
> Luckily, you provided your reasoning below:
>
> > Questions that pop where previously Emacs did something 
> > silently can
> > be annoying, which is why I'd prefer to turn this off by 
> > default.  If
> > someone wants the new behavior, they can enable it.
>
> That's fair enough.  To me, the danger of accidentally deleting a
> bookmarks still seems more important.  On the one hand, we have 
> lived
> with that for a long time, OTOH that is no reason not to try to 
> do
> better.

I agree with Stefan's reasoning here.

Backward compatibility is a big deal in an API, but it's a much 
smaller deal in an interactive interface behavior.  Yes, users 
will be prompted in a place where they weren't prompted before, 
but the prompt is self-explanatory, and the old behavior was 
needlessly dangerous -- it's easy to type "x" accidentally and 
lose bookmarks marked for deletion before one had finalized the 
list.

If someone had suggested this when I was first implementing the 
Bookmark Menu, I think I would have incorporated the suggestion 
then and just had this behavior from the beginning.  The fact that 
it's a change in interactive behavior now is minor compared to the 
benefit.

I agree that it should get a NEWS entry, of course, and agree with 
Lars' suggestions of `:version' and some documentation tweaks. 

Regarding the question of using an undo-based method instead:

Lars Ingebrigtsen wrote:
> In general, I think it's better to offer undo instead of 
> prompting.
> That's not always possible, but I think in the bookmark case, 
> that
> shouldn't be too difficult -- just register an undo action that 
> inserts
> the items that were removed, I think?

I think that's not as good as the confirmation-prompt here, for 
two reasons.  One, the discoverability issue raised by Stefan 
Kangas in his reply; two, Bookmark Menu has a similar basic 
look-and-feel to Dired Mode, with which many users are probably 
already familiar, and Dired does exactly this kind of confirmation 
prompt by default for deleting files.  If Bookmark just behaves 
the way Dired does by default, that would be consistent with [at 
least some] users' expectations.

Best regards,
-Karl