From fd5539c6de4df242b517a73ced2fc1ff1f661227 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Agust=C3=ADn=20Mart=C3=ADn?= <agustin.martin@hispalinux.es>
Date: Wed, 7 Jul 2010 12:30:57 +0200
Subject: [PATCH] Improve ispell.el word completion handling.

* ispell.el (ispell-alternate-dictionary): Use file-readable-p.
  Return nil if no word-list is found at default locations.
 (ispell-complete-word-dict): Default to nil.
 (ispell-command-loop): Use 'word-list' when using lookup-words.
 (lookup-words): Use ispell-complete-word-dict or
 ispell-alternate-dictionary.  Check for word-list availability
 and handle errors if needed with better messages (Bug#6539).
 (ispell-complete-word): Use ispell-complete-word-dict or
 ispell-alternate-dictionary.
---
 lisp/ChangeLog           | 12 +++++++++++
 lisp/textmodes/ispell.el | 45 +++++++++++++++++++++++++---------------
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 2214a6ba761..6fef9173109 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,15 @@
+2010-07-07  Agustín Martín  <agustin.martin@hispalinux.es>
+
+	* ispell.el (ispell-alternate-dictionary): Use file-readable-p.
+	Return nil if no word-list is found at default locations.
+	(ispell-complete-word-dict): Default to nil.
+	(ispell-command-loop): Use 'word-list' when using lookup-words.
+	(lookup-words): Use ispell-complete-word-dict or
+	ispell-alternate-dictionary.  Check for word-list availability
+	and handle errors if needed with better messages (Bug#6539).
+	(ispell-complete-word): Use ispell-complete-word-dict or
+	ispell-alternate-dictionary.
+
 2010-07-07  Glenn Morris  <rgm@gnu.org>
 
 	* play/zone.el (top-level): Do not require timer, tabify, or cl.
diff --git a/lisp/textmodes/ispell.el b/lisp/textmodes/ispell.el
index a9915fcfb17..ad591eb0e7f 100644
--- a/lisp/textmodes/ispell.el
+++ b/lisp/textmodes/ispell.el
@@ -357,21 +357,21 @@ Must be greater than 1."
   :group 'ispell)
 
 (defcustom ispell-alternate-dictionary
-  (cond ((file-exists-p "/usr/dict/web2") "/usr/dict/web2")
-	((file-exists-p "/usr/share/dict/web2") "/usr/share/dict/web2")
-	((file-exists-p "/usr/dict/words") "/usr/dict/words")
-	((file-exists-p "/usr/lib/dict/words") "/usr/lib/dict/words")
-	((file-exists-p "/usr/share/dict/words") "/usr/share/dict/words")
-	((file-exists-p "/usr/share/lib/dict/words")
+  (cond ((file-readable-p "/usr/dict/web2") "/usr/dict/web2")
+	((file-readable-p "/usr/share/dict/web2") "/usr/share/dict/web2")
+	((file-readable-p "/usr/dict/words") "/usr/dict/words")
+	((file-readable-p "/usr/lib/dict/words") "/usr/lib/dict/words")
+	((file-readable-p "/usr/share/dict/words") "/usr/share/dict/words")
+	((file-readable-p "/usr/share/lib/dict/words")
 	 "/usr/share/lib/dict/words")
-	((file-exists-p "/sys/dict") "/sys/dict")
-	(t "/usr/dict/words"))
-  "*Alternate dictionary for spelling help."
+	((file-readable-p "/sys/dict") "/sys/dict"))
+  "*Alternate plain word-list dictionary for spelling help."
   :type '(choice file (const :tag "None" nil))
   :group 'ispell)
 
-(defcustom ispell-complete-word-dict ispell-alternate-dictionary
-  "*Dictionary used for word completion."
+(defcustom ispell-complete-word-dict nil
+  "*Plain word-list dictionary used for word completion if
+different from `ispell-alternate-dictionary'."
   :type '(choice file (const :tag "None" nil))
   :group 'ispell)
 
@@ -2049,10 +2049,11 @@ Global `ispell-quit' set to start location to continue spell session."
 			      (erase-buffer)
 			      (setq count ?0
 				    skipped 0
-				    mode-line-format
+				    mode-line-format ;; setup the *Choices* buffer with valid data.
 				    (concat "--  %b  --  word: " new-word
-					    "  --  dict: "
-					    ispell-alternate-dictionary)
+					    "  --  word-list: "
+					    (or ispell-complete-word-dict
+						ispell-alternate-dictionary))
 				    miss (lookup-words new-word)
 				    choices miss
 				    line ispell-choices-win-default-height)
@@ -2267,11 +2268,20 @@ Otherwise the variable `ispell-grep-command' contains the command used to
 search for the words (usually egrep).
 
 Optional second argument contains the dictionary to use; the default is
-`ispell-alternate-dictionary'."
+`ispell-alternate-dictionary', overriden by `ispell-complete-word-dict'
+if defined."
   ;; We don't use the filter for this function, rather the result is written
   ;; into a buffer.  Hence there is no need to save the filter values.
   (if (null lookup-dict)
-      (setq lookup-dict ispell-alternate-dictionary))
+      (setq lookup-dict (or ispell-complete-word-dict
+			    ispell-alternate-dictionary)))
+
+  (if lookup-dict
+      (unless (file-readable-p lookup-dict)
+	(error "lookup-words error: Unreadable or missing plain word-list %s."
+	       lookup-dict))
+    (error (concat "lookup-words error: No plain word-list found at system default "
+		   "locations.  Customize `ispell-alternate-dictionary' to set yours.")))
 
   (let* ((process-connection-type ispell-use-ptys-p)
 	 (wild-p (string-match "\\*" word))
@@ -3342,7 +3352,8 @@ Standard ispell choices are then available."
 	      (lookup-words (concat (and interior-frag "*") word
 				    (if (or interior-frag (null ispell-look-p))
 					"*"))
-			    ispell-complete-word-dict)))
+			    (or ispell-complete-word-dict
+				ispell-alternate-dictionary))))
     (cond ((eq possibilities t)
 	   (message "No word to complete"))
 	  ((null possibilities)