On Mon, 2 Nov 2020 at 16:10, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Reuben Thomas <rrt@sc3d.org>
> > Date: Mon, 2 Nov 2020 15:49:19 +0000
> > Cc: dinkonin <dinkonin@gmail.com>, 44318@debbugs.gnu.org
> >
> > So I, as upstream maintainer, am telling you that indeed, it is not
> correct that Emacs should take
> > enchant-lsmod's stderr as part of its output! (As I said above, it would
> be possible to capture stderr
> > separately and display it to the user, though I don't recommend that
> currently, because the warnings are not
> > written for users. Other programs that use Enchant do not show these
> warnings, they simply omit providers
> > that do not load from the list of languages/spelling checkers that are
> available.)
>
> OK, I agree to this change, under protest.
>

Thanks Eli, I have installed it; of course, contact me if it causes any
problems. After installing that patch, I discovered that in
ispell--call-enchant-lsmod, it did need to use with-current-buffer, so I
have installed a patch that restores the use of with-current-buffer;
apologies for getting that wrong first time.

In fact, this change is not sufficient to fix the original problem, because
the enchant program outputs the same warning when a provider module cannot
be loaded. In this case, stderr is added to the list of suggested words.
Again, I believe Enchant is correct to output a warning, and again, I
believe Emacs is wrong to amalgamate stderr and stdout.

I attach three patches that do the following:

1. Simplify ispell-call-process{,-region} by factoring out the macro
ispell-with-safe-default-directory.

2. I also found that ispell-check-version can be simplified slightly:
aspell has accepted -vv since 2004, so use it always.
3. When spell-checking, collect only standard output. This leaves some
spell-checker-specific calls to ispell-call-process to collect stderr as
well, which as far as I can tell is needed in only one case,
ispell-find-hunspell-dictionaries; but it doesn't hurt to leave the rest
unchanged. I have tested this patch with all supported spellcheckers
(ispell, aspell, hunspell, enchant).