bug#63896: [PATCH] Support annotating and sorting the project list during completion

[Eli Zaretskii]

> Date: Thu, 24 Aug 2023 16:08:04 +0300
> Cc: sbaugh@janestreet.com, 63896@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 24/08/2023 08:29, Eli Zaretskii wrote:
> >> Date: Thu, 24 Aug 2023 04:54:44 +0300
> >> Cc:63896@debbugs.gnu.org
> >> From: Dmitry Gutov<dmitry@gutov.dev>
> >>
> >> On 05/06/2023 14:23, Eli Zaretskii wrote:
> >>>> +                (format-mode-line mode-line-process nil nil buf)))
> >>> Do you really need to call format-mode-line?  My advice is to stay
> >>> away of that function: it could have unpleasant side effects.
> >> Does calling format-mode-line trigger extra redisplays or something?
> >> That sounds unexpected.
> > It reuses parts of the redisplay's code, yes.  Depending what's in the
> > format variable passed to format-mode-line, that could cause a variety
> > of surprises, especially if :eval forms are involved.  It could also
> > temporarily select another window and/or buffer, if the respective
> > arguments are not omitted, which could also be unexpected.
> > 
> > IMO, this function should be used sparing and with caution.
> 
> All right, so I guess it's the same concern: when mode-line-process 
> contains something unusual, possibly assigned by a derived mode.

Yes.