bug#81514: 32.0.50; Eglot messages progress reporter shows errors

Stéphane Marks [05/Aug  3:56pm +02] wrote:
> On Wed, Aug 5, 2026 at 7:34 AM Sean Whitton <[email protected]>
> wrote:
>
>> João Távora [05/Aug 12:19pm +01] wrote:
>> > On Wed, Aug 5, 2026, 12:15 João Távora <[email protected]> wrote:
>> >
>> >> Afaik, while Eglot had its shortcomings in its usage of progress
>> >> reporters, now hopefully fixed, the real trigger for this regression
>> was a
>> >> backward incompatible change in progress reporters. Presumably Stéphane
>> 's
>> >> patch addresses that. If you don't install it, it could be that other
>> Elisp
>> >> code out there making similar poor usage of reporters as Eglot did until
>> >> now will start breaking.
>> >>
>> >
>> > [ Sorry sent too early.]
>> >
>> > ...anyway, could be a risk worth taking for the general improvement of
>> > things, or not. Maintenance policy call... In any case, if so, it should
>> be
>> > listed under backward incompatible Lisp changes.
>>
>> Thanks, though I don't think I yet see what's backwards incompatible
>> about it.  I'd like to know exactly what this is trying to fix and how.
>>
>
> The one-line patch fixes the cases where a progress-reporter-update caller
> does not follow the strict API that UPDATE-TEXT is a string, or when
> missing, VALUE should be a string.  The now fixed eglot call to
> progress-reporter-update using the numeric interface with a non-numeric
> (pulsing) reporter tickled the type mismatch.  Our fix below is a defensive
> fix should other progress reporter calls make the same mistake and will
> prevent signaling an error in innocuous situations such as the eglot case
> that was caught by a keen-eyed eglot user.
>
> -      (setq update-text (concat (if update-text " " "") update-text))
> +      (setq update-text (if update-text (format " %s" update-text) ""))

You and João seem to disagree about the status of this fix.  He thinks
it's an incompatible change, you think it's innocuous.  Is that right?
Do you think it's not an incompatible change?

-- 
Sean Whitton