bug#26274: 26.0.50; completion regression

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: Eli Zaretskii <eliz@gnu.org>,  26274@debbugs.gnu.org
> Date: Wed, 29 Mar 2017 22:00:27 +0200
> 
> > Starting from a fresh checkout like Eli suggested is the safest way,
> > but I guess you should be able to get around this error by deleting
> > 'Makefile', and regenerating it by running ./configure again.
> 
> Thanks, I went this route, and it worked (and still took almost an hour
> to go through eight iterations).  Git bisect in fact pinpointed this
> commit:
> 
> 5ec3a58462e99533ea5200de356302181d634d0b is the first bad commit
> commit 5ec3a58462e99533ea5200de356302181d634d0b
> Author: Michal Nazarewicz <mina86@mina86.com>
> Date:   Mon Sep 19 00:23:40 2016 +0200
> 
>     Generate upcase and downcase tables from Unicode data  (bug#24603)
>     
>     Use Unicode data to generate case tables instead of mostly repeating
>     them in lisp code.  Do that in a way which maps ‘Dz’ (and similar)
>     digraph to ‘dz’ when down- and ‘DZ’ when upcasing.
>     
>     https://debbugs.gnu.org/cgi/bugreport.cgi?msg=89;bug=24603 lists all
>     changes to syntax table and case tables introduced by this commit.
>     
>     * lisp/international/characters.el: Remove case-pairs defined with
>     explicit Lisp code and instead use Unicode character properties.
>     
>     * test/src/casefiddle-tests.el (casefiddle-tests--characters,
>     casefiddle-tests-casing): Update test cases which are now working
>     as they should.
> 
> (When Eli listed this as a candidate, I doubted it because of the date,
> since my build from February 8 of this year does not have the problem.
> I guess that date is not the commit date.  Confusing when looking at the
> commit log.)

The commit date is Feb 15.  This commit came from a feature branch, so
the date you see in the log I show is the original commit date on that
branch.

Michal, could you please take a look at this?