bug#34272: 26.1.91 M-x flyspell-mode

[Tak Kunihiro <tkk@misasa.okayama-u.ac.jp>]

>> I traced `ispell-find-hunspell-dictionaries' using Edebug.  I have an
>> impression, problem is something to do with initialization on
>> `hunspell-default-dict'.  The output is shown below.
> 
> hunspell-default-dict is computed in this function,
> ispell-find-hunspell-dictionaries.  It starts as nil, and then the
> function iterates through the list of dictionaries produced by the
> command "hunspell -D nul", looking for a dictionary name that ends
> with a ".aff".  Here's the relevant portion of the code:
> 
>   (let ((hunspell-found-dicts
> 	 (split-string
> 	  (with-temp-buffer
> 	    (ispell-call-process ispell-program-name
> 				 null-device
> 				 t
> 				 nil
>                                  ;; Hunspell 1.7.0 (and later?) won't
>                                  ;; show LOADED DICTIONARY unless
>                                  ;; there's at least one file argument
>                                  ;; on the command line.  So we feed
>                                  ;; it with the null device.
> 				 "-D" null-device)
> 	    (buffer-string))
> 	  "[\n\r]+"
> 	  t))


I think that I found issue.  In my environment, `ispell-call-process'
returns empty string with `null-device'.

Output with and without `null-device' is shown below.



* With `null-device'

(with-temp-buffer
  (ispell-call-process ispell-program-name
 				       null-device
 				       t
 				       nil
                       ;; Hunspell 1.7.0 (and later?) won't
                       ;; show LOADED DICTIONARY unless
                       ;; there's at least one file argument
                       ;; on the command line.  So we feed
                       ;; it with the null device.
 				       "-D" null-device)
  (buffer-string))                      ; => ""


* Without `null-device',

(with-temp-buffer
  (ispell-call-process ispell-program-name
 				       null-device
 				       t
 				       nil
                       ;; Hunspell 1.7.0 (and later?) won't
                       ;; show LOADED DICTIONARY unless
                       ;; there's at least one file argument
                       ;; on the command line.  So we feed
                       ;; it with the null device.
 				       "-D")
  (buffer-string))                      ; => see below

"SEARCH PATH:
.;c:/msys64/mingw64/bin/;c:/msys64/mingw64/share/hunspell;c:/msys64/mingw64/share/myspell;c:/msys64/mingw64/share/myspell/dicts;c:/msys64;%USERPROFILE%/Application Data/OpenOffice.org 2/user/wordbook;c:/msys64/mingw64/share/dict/ooo;
AVAILABLE DICTIONARIES (path is not mandatory for -d option):
c:/msys64/mingw64/share/hunspell/en_AG
...
c:/msys64/mingw64/share/hunspell/en_ZW
c:/msys64/mingw64/share/myspell/dicts/en_AG
...
c:/msys64/mingw64/share/myspell/dicts/en_ZW
LOADED DICTIONARY:
c:/msys64/mingw64/share/hunspell/en_US.aff
c:/msys64/mingw64/share/hunspell/en_US.dic
Hunspell 1.6.2
"