bug#42248: 27.0.91; With enchant-2.2.8 from Guix, Flyspell errors out or gives lots of false positives

[Jorge P . de Morais Neto]

Em [2020-08-20 qui 16:18:01+0300], Eli Zaretskii escreveu:

> Do you see the same problem when you invoke Enchant from the shell
> prompt?

Yes, enchant-2 on the command line misreports numbers:
$ enchant-2 -d en_US -l /tmp/enchant-test.txt
2015
Casa
42

$ enchant-2 -d pt_BR -l /tmp/enchant-test.txt
doesn't
2015
42

The file /tmp/enchant-test.txt:
--8<---------------cut here---------------start------------->8---
doesn't 2015
Casa 42
--8<---------------cut here---------------end--------------->8---

> The examples you provided all work fine for me, although not with
> Enchant, so I'm inclined to think this is an Enchant problem.  Or
> maybe they modified the interface, making it no longer compatible with
> ispell.el.  In the latter case, someone with access to Enchant will
> have to tell us how to modify ispell.el to adapt to the Enchant
> changes.
>
> The error message shown in your original report seems to indicate that
> our invocation of Enchant is somehow incorrect, but there isn't enough
> information there to understand what is incorrect and how to fix that.

I should have given you the value of ispell-dictionary-alist.  Sorry.
This time I will.  So, after executing the following recipe:

1. emacs -Q
2. Evaluate:
    (progn
                 (setq ispell-program-name "enchant-2")
                 (ispell-change-dictionary "en_US")
                 (insert "doesn't 2015")
                 (ispell-buffer))

Then invoking
C-h v ispell-dictionary-alist <RET>
displays the following value:

--8<---------------cut here---------------start------------->8---
((nil "[[:alpha:]]" "[^[:alpha:]]" #1="" t nil nil utf-8)
 ("pt_BR" #2="[[:alpha:]]" #3="[^[:alpha:]]" #1# t nil nil utf-8)
 ("en_GB" #2# #3# #1# t nil nil utf-8)
 ("en_AU" #2# #3# #1# t nil nil utf-8)
 ("en_US" #2# #3# #1# t nil nil utf-8)
 ("en" #2# #3# #1# t nil nil utf-8)
 ("en_CA" #2# #3# #1# t nil nil utf-8)
 ("" #2# #3# #1# t nil nil utf-8)
 ("american" "[A-Za-z]" "[^A-Za-z]" "[']" nil
  ("-B" #4="-d" "en_US")
  nil utf-8)
 ("brasileiro" 
"[A-Z\301\311\315\323\332\300\310\314\322\331\303\325\307\334\302\312\324a-z\341\351\355\363\372\340\350\354\362\371\343\365\347\374\342\352\364]"
 
"[^A-Z\301\311\315\323\332\300\310\314\322\331\303\325\307\334\302\312\324a-z\341\351\355\363\372\340\350\354\362\371\343\365\347\374\342\352\364]"
 "[']" nil nil nil utf-8)
 ("british" "[A-Za-z]" "[^A-Za-z]" "[']" nil
  ("-B" #4# "en_GB")
  nil utf-8)
 ("castellano" 
"[A-Z\301\311\315\321\323\332\334a-z\341\351\355\361\363\372\374]" 
"[^A-Z\301\311\315\321\323\332\334a-z\341\351\355\361\363\372\374]" "[-]" nil
  ("-B" #4# "es_ES")
  "~tex" utf-8)
 ("castellano8" 
"[A-Z\301\311\315\321\323\332\334a-z\341\351\355\361\363\372\374]" 
"[^A-Z\301\311\315\321\323\332\334a-z\341\351\355\361\363\372\374]" "[-]" nil
  ("-B" "-d" "castellano")
  "~latin1" utf-8)
 ("czech" 
"[A-Za-z\301\311\314\315\323\332\331\335\256\251\310\330\317\253\322\341\351\354\355\363\372\371\375\276\271\350\370\357\273\362]"
 
"[^A-Za-z\301\311\314\315\323\332\331\335\256\251\310\330\317\253\322\341\351\354\355\363\372\371\375\276\271\350\370\357\273\362]"
 #1# nil
  ("-B" #4# "cs_CZ")
  nil utf-8)
 ("dansk" "[A-Z\306\330\305a-z\346\370\345]" 
"[^A-Z\306\330\305a-z\346\370\345]" "[']" nil
  ("-C" #4# "da_DK")
  nil utf-8)
 ("deutsch" "[a-zA-Z\"]" "[^a-zA-Z\"]" "[']" t
  ("-C" #4# "de_DE")
  "~tex" utf-8)
 ("deutsch8" "[a-zA-Z\304\326\334\344\366\337\374]" 
"[^a-zA-Z\304\326\334\344\366\337\374]" "[']" t
  ("-C" "-d" "deutsch")
  "~latin1" utf-8)
 ("english" "[A-Za-z]" "[^A-Za-z]" "[']" nil
  ("-B" #4# "en_US")
  nil utf-8)
 ("esperanto" "[A-Za-z\246\254\266\274\306\330\335\336\346\370\375\376]" 
"[^A-Za-z\246\254\266\274\306\330\335\336\346\370\375\376]" "[-']" t
  ("-C" #4# "eo")
  "~latin3" utf-8)
 ("esperanto-tex" "[A-Za-z^\\]" "[^A-Za-z^\\]" "[-'`\"]" t
  ("-C" "-d" "esperanto")
  "~tex" utf-8)
 ("finnish" "[A-Za-z\345\344\366\305\304\326]" 
"[^A-Za-z\345\344\366\305\304\326]" "[:]" nil
  ("-C" #4# "fi_FI")
  "~list" utf-8)
 ("francais7" "[A-Za-z]" "[^A-Za-z]" "[`'^-]" t nil nil utf-8)
 ("francais" 
"[A-Za-z\300\302\306\307\310\311\312\313\316\317\324\331\333\334\340\342\347\350\351\352\353\356\357\364\371\373\374]"
 
"[^A-Za-z\300\302\306\307\310\311\312\313\316\317\324\331\333\334\340\342\347\350\351\352\353\356\357\364\371\373\374]"
 "[-'.@]" t nil "~list" utf-8)
 ("francais-tex" 
"[A-Za-z\300\302\306\307\310\311\312\313\316\317\324\331\333\334\340\342\347\350\351\352\353\356\357\364\371\373\374\\]"
 
"[^A-Za-z\300\302\306\307\310\311\312\313\316\317\324\331\333\334\340\342\347\350\351\352\353\356\357\364\371\373\374\\]"
 "[-'^`\".@]" t nil "~tex" utf-8)
 ("german" "[a-zA-Z\"]" "[^a-zA-Z\"]" "[']" t
  ("-C" #4# "de_DE")
  "~tex" utf-8)
 ("german8" "[a-zA-Z\304\326\334\344\366\337\374]" 
"[^a-zA-Z\304\326\334\344\366\337\374]" "[']" t
  ("-C" "-d" "german")
  "~latin1" utf-8)
 ("italiano" 
"[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
  ("-B" "-d" "italian")
  "~tex" utf-8)
 ("nederlands" 
"[A-Za-z\300\301\302\303\304\305\307\310\311\312\313\314\315\316\317\322\323\324\325\326\331\332\333\334\340\341\342\343\344\345\347\350\351\352\353\354\355\356\357\361\362\363\364\365\366\371\372\373\374]"
 
"[^A-Za-z\300\301\302\303\304\305\307\310\311\312\313\314\315\316\317\322\323\324\325\326\331\332\333\334\340\341\342\343\344\345\347\350\351\352\353\354\355\356\357\361\362\363\364\365\366\371\372\373\374]"
 "[']" t
  ("-C" #4# "nl_NL")
  nil utf-8)
 ("nederlands8" 
"[A-Za-z\300\301\302\303\304\305\307\310\311\312\313\314\315\316\317\322\323\324\325\326\331\332\333\334\340\341\342\343\344\345\347\350\351\352\353\354\355\356\357\361\362\363\364\365\366\371\372\373\374]"
 
"[^A-Za-z\300\301\302\303\304\305\307\310\311\312\313\314\315\316\317\322\323\324\325\326\331\332\333\334\340\341\342\343\344\345\347\350\351\352\353\354\355\356\357\361\362\363\364\365\366\371\372\373\374]"
 "[']" t
  ("-C" #4# "nl_NL")
  nil utf-8)
 ("norsk" 
"[A-Za-z\305\306\307\310\311\322\324\330\345\346\347\350\351\362\364\370]" 
"[^A-Za-z\305\306\307\310\311\322\324\330\345\346\347\350\351\362\364\370]" 
"[\"]" nil nil "~list" utf-8)
 ("norsk7-tex" "[A-Za-z{}\\'^`]" "[^A-Za-z{}\\'^`]" "[\"]" nil
  ("-d" "norsk")
  "~plaintex" utf-8)
 ("polish" 
"[A-Za-z\241\243\246\254\257\261\263\266\274\277\306\312\321\323\346\352\361\363]"
 
"[^A-Za-z\241\243\246\254\257\261\263\266\274\277\306\312\321\323\346\352\361\363]"
 "[.]" nil nil nil utf-8)
 ("portugues" 
"[a-zA-Z\301\302\307\311\323\340\341\342\351\352\355\363\343\347\372]" 
"[^a-zA-Z\301\302\307\311\323\340\341\342\351\352\355\363\343\347\372]" "[']" t
  ("-C" #4# "pt_PT")
  "~latin1" utf-8)
 ("russian" 
"[\341\342\367\347\344\345\263\366\372\351\352\353\354\355\356\357\360\362\363\364\365\346\350\343\376\373\375\370\371\377\374\340\361\301\302\327\307\304\305\243\326\332\311\312\313\314\315\316\317\320\322\323\324\325\306\310\303\336\333\335\330\331\337\334\300\321]"
 
"[^\341\342\367\347\344\345\263\366\372\351\352\353\354\355\356\357\360\362\363\364\365\346\350\343\376\373\375\370\371\377\374\340\361\301\302\327\307\304\305\243\326\332\311\312\313\314\315\316\317\320\322\323\324\325\306\310\303\336\333\335\330\331\337\334\300\321]"
 #1# nil nil nil utf-8)
 ("russianw" 
"[\300\301\302\303\304\305\250\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\334\333\332\335\336\337\340\341\342\343\344\345\270\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\374\373\372\375\376\377]"
 
"[^\300\301\302\303\304\305\250\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\334\333\332\335\336\337\340\341\342\343\344\345\270\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\374\373\372\375\376\377]"
 #1# nil nil nil utf-8)
 ("slovak" 
"[A-Za-z\301\304\311\315\323\332\324\300\305\245\335\256\251\310\317\253\322\341\344\351\355\363\372\364\340\345\265\375\276\271\350\357\273\362]"
 
"[^A-Za-z\301\304\311\315\323\332\324\300\305\245\335\256\251\310\317\253\322\341\344\351\355\363\372\364\340\345\265\375\276\271\350\357\273\362]"
 #1# nil
  ("-B" #4# "sk_SK")
  nil utf-8)
 ("slovenian" 
"[A-Za-z\301\304\311\315\323\332\324\300\305\245\335\256\251\310\317\253\322\341\344\351\355\363\372\364\340\345\265\375\276\271\350\357\273\362]"
 
"[^A-Za-z\301\304\311\315\323\332\324\300\305\245\335\256\251\310\317\253\322\341\344\351\355\363\372\364\340\345\265\375\276\271\350\357\273\362]"
 #1# nil
  ("-B" "-d" "slovenian")
  nil utf-8)
 ("svenska" 
"[A-Za-z\345\344\366\351\340\374\350\346\370\347\305\304\326\311\300\334\310\306\330\307]"
 
"[^A-Za-z\345\344\366\351\340\374\350\346\370\347\305\304\326\311\300\334\310\306\330\307]"
 "[']" nil
  ("-C" #4# "sv_SE")
  "~list" utf-8)
 ("hebrew" 
"[\340\341\342\343\344\345\346\347\350\351\353\352\354\356\355\360\357\361\362\364\363\367\366\365\370\371\372]"
 
"[^\340\341\342\343\344\345\346\347\350\351\353\352\354\356\355\360\357\361\362\364\363\367\366\365\370\371\372]"
 #1# nil
  ("-B" #4# "he_IL")
  nil utf-8))
--8<---------------cut here---------------end--------------->8---

Therefore, the list for "american" specifies `("-B" #4="-d" "en_US")' as
ISPELL-ARGS.  However, enchant-2 does not take a "-B" flag:

$ enchant-2 -B -d en_US /tmp/enchant-test.txt
Usage: enchant-2 -a|-l|-h|-v [-L] [-d DICTIONARY] [FILE]
  -d DICTIONARY  use the given dictionary
  -a             list suggestions in ispell pipe mode format
  -l             list only the misspellings
  -L             display line numbers
  -h             display help and exit
  -v             display version information and exit

$ enchant-2 -B -d en_US -l /tmp/enchant-test.txt
Usage: enchant-2 -a|-l|-h|-v [-L] [-d DICTIONARY] [FILE]
  -d DICTIONARY  use the given dictionary
  -a             list suggestions in ispell pipe mode format
  -l             list only the misspellings
  -L             display line numbers
  -h             display help and exit
  -v             display version information and exit


Also, the list for "en_US" specifies "" for OTHERCHARS, but, IIUC, it
ought to be "[']" instead.

In fact, I just apparently found a workaround for the Flyspell problem
with contractions.

1. emacs -Q
2. Evaluate
    (progn
                 (setq ispell-program-name "enchant-2")
                 (ispell-change-dictionary "en_US")
                 (setf (cadddr (assoc "en_US" ispell-dictionary-alist)) (cadddr 
(assoc "american" ispell-dictionary-alist)))
                 (insert "doesn't 2015")
                 (flyspell-buffer))

Unfortunately this workaround did not solve the problem of ispell-buffer
misreporting with numbers.  Anyway, I will test it for longer, then
later I will report whether it really solved the Flyspell contraction
problem.

Regards

-- 
- <https://jorgemorais.gitlab.io/justice-for-rms/>
- I am Brazilian.  I hope my English is correct and I welcome feedback.
- <https://www.defectivebydesign.org/>
- <https://www.gnu.org/>