bug#25219: 26.0.50; ispell failing

[Eli Zaretskii <eliz@gnu.org>]

> From: Alan Third <alan@idiocy.org>
> Date: Sun, 18 Dec 2016 11:51:37 +0000
> Cc: 25219@debbugs.gnu.org
> 
> > run M-x ispell-buffer
> >
> > watch it fail on fist word not in dictionry
> >
> > I use ispell before sending mail (dyslexia and sspect keyboad)
> >
> > een this way fo a week or so
> 
> It looks like this started with commit:
> 
> db6e1f82976a7f232a4a206a3c850ed34cfbfdd3
> 
> The following patch appears to fix the problem for me, but I have my
> doubts it's the best way to handle it and I've only tested with
> hunspell.
> 
> modified   lisp/textmodes/ispell.el
> @@ -3338,7 +3338,7 @@ ispell-process-line
>  	  ;; Markers can move with highlighting!  This destroys
>  	  ;; end of region markers line-end and ispell-region-end
>  	  (let ((word-start
> -		 (copy-marker (+ ispell-start (car (cdr poss)))))
> +		 (copy-marker (+ ispell-start -1 (car (cdr poss)))))
>  		(word-len (length (car poss)))
>  		(line-end (copy-marker ispell-end))
>  		(line-start (copy-marker ispell-start))
> 
> Any thoughts?

We definitely need to keep the -1 offset there.  (It was previously
supplied by ispell-offset, but that variable was deleted.)  The reason
for the offset is that the line we send to the speller has a "^"
prepended to it (see the documentation of the Ispell interface for the
reason why).

Please add a comment to that effect when you commit the above.

Thanks.