bug#48356: 28.0.50; choose-completion discards the suffix after the completion boundary

[Juri Linkov]

>>>> IMHO, the root of the problem is in completion-all-completions
>>>> that returns in the last `cdr' only the start of completions,
>>>> but not the end of completions.
>>>
>>> Agreed.
>>
>> If I recall correctly, someone wrote a patch which fixed the root cause.
>
> The only patch that removes these comments
>
>         ;; FIXME: We need to additionally return the info needed for the
>         ;; second part of completion-base-position.
>
>         ;; FIXME: We should pay attention to completion
>         ;; boundaries here, but currently
>         ;; completion-all-completions does not give us the
>         ;; necessary information.
>
> is https://lists.gnu.org/archive/html/emacs-devel/2021-08/msg00412.html
> in bug#47711 and bug#48841.

I wonder what is the fate of this patch?  There was a long discussion
without a clear outcome.  Maybe it's possible to split the patch
to smaller parts where a separate patch would add the feature needed here
to return the end position of the completion boundaries?