bug#39898: 28.0.50; The off-by-one bug in `flyspell-check-previous-highlighted-word'

[OGAWA Hirofumi]

With the following test,

(with-temp-buffer
  (select-window (display-buffer (current-buffer)))
  (insert "appl")
  (flyspell-buffer)
  (flyspell-check-previous-highlighted-word))

`flyspell-check-previous-highlighted-word' calls `(error)'.  But "appl"
is the typo that should be fixed.

At the following [**] mark in a that command, the ">" looks not allowing
a typo at (point-min). Maybe the ">" should be the ">=".

(defun flyspell-check-previous-highlighted-word (&optional arg)

[...]

            (if (> pos (point-min))      <- [**]

[...]

        (save-excursion
          (goto-char pos)
          (ispell-word)
          (setq flyspell-word-cache-word nil) ;; Force flyspell-word re-check
          (flyspell-word))
      (error "No word to correct before point"))))



In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.13, cairo 
version 1.16.0)
 of 2020-03-04 built on devron
Repository revision: cf45e8022ee182529668c0d50d27b4e168331e97
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12007000
System Description: Debian GNU/Linux bullseye/sid

Recent messages:
Checking new news...
Reading active file via nnnil...done
nnimap read 0k from server.parknet.ne.jp
Reading active file via nndraft...done
Checking new news...done
Checking new news...
Reading active file via nnnil...done
nnimap read 0k from server.parknet.ne.jp
Reading active file via nndraft...done
Checking new news...done

Configured using:
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-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>