Emacs ispell error when accepting words for local file dictionary

Question

In every .tex file, when I type A (shift a) to accept a new word, I get the error message Wrong type argument: sequencep, 1 in the minibuffer or in the message buffer:

ispell-add-per-file-word-list: Wrong type argument: sequencep, 1

If I add, at the bottom of the file, a line similar to the following:

% LocalWords:  hello

I get can (A)ccept a limited number of words, by and large up to 50 characters of new words, that is up to the end of the line. Then I get the same error again. If I add another line like the previous, therefore:

% LocalWords:  hello <words added by ispell ...>
% LocalWords:  again 

I can go on again up to the end of the line. Thereafter the error shows again.

As for my init file, I have these apparently innocent lines:

(setenv "DICPATH" (concat exec-directory "../hunspell/dict"))
(setq-default ispell-program-name
  (concat exec-directory "../hunspell/hunspell.exe"))
(setq ispell-extra-args '("-t"))
(setq ispell-local-dictionary-alist
      '(
        (nil       "[A-Za-z]" "[^A-Za-z]" "[']" nil ("-d" "en_US") nil utf-8)
        ("english" "[A-Za-z]" "[^A-Za-z]" "['.]"    nil ("-d" "en_GB") nil utf-8)

        ("italian"
"[A-Z\300\301\310\311\314\315\322\323\331\332a-z\340\341\350\351\354\355\363\371\372]"
 "[^A-Z\300\301\310\311\314\315\322\323\331\332a-z\340\341\350\351\354\355\363\371\372]"
        "[-.]" nil ("-d" "it_IT") nil iso-8859-1)

        ))

In summary, whenever it is time to start a new line of the local file dictionary, ispell-add-per-file-word-list gets into troubles.

Answer 1

This suggested workaround fixes the problem for me. Excerpting it here for posterity, the workaround is to add the following to your Emacs start-up code:

(add-hook 'TeX-mode-hook #'(lambda ()
                             (setq-local comment-padding " ")))

The root cause is an Emacs bug that has subsequently been fixed. So this problem should go away entirely in Emacs 24.4 and later.