bug#50470: 27.1; 'company-mode' 'eshell'

[Dmitry Gutov]

It seems like this bug was fixed in bug#55204?

Or at least the problems scenarios are not reproducible anymore.

The downside compared to my latest patch is that it actually expanded 
~/Downl* into a bunch of completions (and the current behavior is "no 
completions"), but that seems minor.

It might be considered a regression, though.

On 26.01.2022 01:05, Stefan Monnier wrote:
> Hi John,
>
> Could you explain to me some of the code of `pcomplete-parse-arguments`?
> I know that was many years ago but hopefully there's still some fond
> memories of how you designed it.
>
> To be honest, the only part I sort-of understand are the first
> 5-6 lines.  Then comes the `(let ((begin (pcomplete-begin 'last)))` and
> after that I'm lost: it doesn't look like we're parsing arguments
> any more.
>
> E.g. Why/when would pcomplete-stub contain a list rather than a string?
>
>
>          Stefan
>
>
> Dmitry Gutov [2022-01-24 03:50:59] wrote:
>
> > Hi Stefan,
> >
> > On 23.01.2022 05:23, Stefan Monnier wrote:
> > > And the 100% untested patch below is a suggestion for how to try and fix
> > > those kinds of bugs.
> > > Can someone try and maybe make it work?
> >
> > I've tried the patch, and it seems to work already, as well as fix this
> > particular scenario. (Thanks!)
> >
> > Might as well install it, I think.
> >
> > There is a scenario that is more noticeably broken (yet actually better with
> > this patch): a modification of bug#18951. Instead of
> >
> >    ls *
> >
> > try
> >
> >    ls ~/Docu*
> >
> > ...and [on master] the result is that the asterisk is replaced with the
> >   "common part" of the possible completions automatically. If there is
> >   nothing to expand with, the asterisk is similarly deleted.
> >
> > With your patch, we get the "Buffer is read-only" error in *Messages*
> > instead, which is probably an improvement. Because it doesn't modify the
> > input, nor break Company completions long-term (after the asterisk is
> > removed).
> >
> > The offending functions is pcomplete-parse-arguments. There is some complex
> > global state going on there, but the following addition seems to fix the
> > problem:
> >
> > @@ -790,6 +804,9 @@ pcomplete-parse-arguments
> >                    (common-stub (car completions))
> >                    (c completions)
> >                    (len (length common-stub)))
> > +              (unless pcomplete-allow-modifications
> > +                (setq pcomplete-stub (buffer-substring begin (point)))
> > +                (throw 'pcomplete-completions completions))
> >               (while (and c (> len 0))
> >                 (while (and (> len 0)
> >                             (not (string=
> >
> >
> > Not sure if this new value of pcomplete-stub is always TRT, but it has
> > passed a bunch of my experiments successfully.