Avoid errors in ispell.el when Enchant returns empty extra chars

* lisp/textmodes/ispell.el (ispell--get-extra-word-characters):
Handle the case of empty extra characters returned by the
Enchant '-lsmod' command. (Bug#31344)

Copyright-paperwork-exempt: yes

diff --git a/lisp/textmodes/ispell.el b/lisp/textmodes/ispell.el
index 88ab7fe1e959e7cf6b8b8e90cff294566dd6161d..3674a7080be83487893cffa707d8c06fc2c4d690 100644 (file)
--- a/lisp/textmodes/ispell.el
+++ b/lisp/textmodes/ispell.el
@@ -1206,8 +1206,10 @@ Internal use.")
 (defun ispell--get-extra-word-characters (&optional lang)
   "Get the extra word characters for LANG as a character class.
 If LANG is omitted, get the extra word characters for the default language."
-  (concat "[" (string-trim-right (apply 'ispell--call-enchant-lsmod
-                                        (append '("-word-chars") (if lang `(,lang))))) "]"))
+  (let ((extra (string-trim-right
+                (apply 'ispell--call-enchant-lsmod
+                       (append '("-word-chars") (if lang `(,lang)))))))
+    (if (string= extra "") "" (concat "[" extra "]"))))
 
 (defun ispell-find-enchant-dictionaries ()
   "Find Enchant's dictionaries, and record in `ispell-enchant-dictionary-alist'."