bug#19653: ispell misalignment with hunspell when Unicode apostrophe is used

[Eli Zaretskii <eliz@gnu.org>]

> From: Joseph Mingrone <jrm@ftfl.ca>
> Date: Fri, 21 Oct 2016 02:04:58 -0300
> 
> This still seems to be a problem with hunspell version 1.3.3.
> 
> The problem can be reproduced by spell checking a file with this one line.
> 
> alsdk ✅ sdfkjdsf sldksdfkjsfd
> 
> During spell checking, the process list shows:
> 
> ispell run -- -- /usr/local/bin/hunspell -a -d en_CA -i UTF-8
> 
> The error Emacs (version 25.1.1) reports is:
> 
> ispell-process-line: Ispell misalignment: word ‘sdfkjdsf’ point 11; probably incompatible versions

Did Hunspell ever fix the problem whereby it reported byte offsets of
the misspelled words, as opposed to character offsets?  If not, that
is your problem, and Hunspell should finally get its act together.

To see whether this is the problem, invoke Hunspell like this:

  /usr/local/bin/hunspell -a -d en_CA -i UTF-8 < test.txt

and see what Hunspell emits.  It should emit something like this (the
below is taken from my system, and I don't have the en_CA dictionary,
so your output might be slightly different):

  @(#) International Ispell Version 3.2.06 (but really Hunspell 1.3.2)
  & alsdk 3 0: Alaska, elastic, Alston
  & sdfkjdsf 2 8: artefact's, postfix
  & sldksdfkjsfd 2 17: justification, staphylococcus

The second number after each misspelled word is the offset of that
word's beginning, measured in characters, from the start of the line.
Hunspell used to report this in bytes instead of characters; if it
still does, you will have to patch it to fix that bug.  AFAIR, the
Hunspell issue tracker includes several patches for this bug.  Or
maybe the latest Hunspell 1.4.1 already fixes this, in which case
please upgrade.