* rfc2047.el (rfc2047-charset-to-coding-system): Add new argument

`allow-override' which says whether to use `mm-charset-override-alist'.
(rfc2047-decode-encoded-words): Use it.

* mm-util.el (mm-charset-override-alist): Fix custom type;
add `(gb2312 . gbk)' to choices.

3 files changed, 53 insertions, 13 deletions

diff --git a/lisp/gnus/ChangeLog b/lisp/gnus/ChangeLog
index 59535f7faa5..3e445c847c1 100644
--- a/lisp/gnus/ChangeLog
+++ b/lisp/gnus/ChangeLog
@@ -1,3 +1,12 @@
+2008-12-10  Katsumi Yamaoka  <yamaoka@jpl.org>
+
+        * rfc2047.el (rfc2047-charset-to-coding-system): Add new argument
+        `allow-override' which says whether to use `mm-charset-override-alist'.
+        (rfc2047-decode-encoded-words): Use it.
+
+        * mm-util.el (mm-charset-override-alist): Fix custom type;
+        add `(gb2312 . gbk)' to choices.
+
 2008-12-04  Katsumi Yamaoka  <yamaoka@jpl.org>
 
         * mm-view.el (mm-inline-text-html-render-with-w3m): Make it simple and
diff --git a/lisp/gnus/mm-util.el b/lisp/gnus/mm-util.el
index 383b1b87916..4630cefc25e 100644
--- a/lisp/gnus/mm-util.el
+++ b/lisp/gnus/mm-util.el
@@ -397,15 +397,42 @@ Unless LIST is given, `mm-codepage-ibm-list' is used."
 You may add pairs like (iso-8859-1 . windows-1252) here,
 i.e. treat iso-8859-1 as windows-1252.  windows-1252 is a
 superset of iso-8859-1."
-  :type '(list (set :inline t
-                    (const (iso-8859-1 . windows-1252))
-                    (const (iso-8859-8 . windows-1255))
-                    (const (iso-8859-9 . windows-1254))
-                    (const (undecided  . windows-1252)))
-               (repeat :inline t
-                       :tag "Other options"
-                       (cons (symbol :tag "From charset")
-                             (symbol :tag "To charset"))))
+  :type
+  '(list
+    :convert-widget
+    (lambda (widget)
+      (let ((defaults
+              (delq nil
+                    (mapcar (lambda (pair)
+                              (if (mm-charset-to-coding-system (cdr pair))
+                                  pair))
+                            '((gb2312 . gbk)
+                              (iso-8859-1 . windows-1252)
+                              (iso-8859-8 . windows-1255)
+                              (iso-8859-9 . windows-1254)
+                              (undecided  . windows-1252)))))
+            (val (copy-sequence (default-value 'mm-charset-override-alist)))
+            pair rest)
+        (while val
+          (push (if (and (prog1
+                             (setq pair (assq (caar val) defaults))
+                           (setq defaults (delq pair defaults)))
+                         (equal (car val) pair))
+                    `(const ,pair)
+                  `(cons :format "%v"
+                         (const :format "(%v" ,(caar val))
+                         (symbol :size 3 :format " . %v)\n" ,(cdar val))))
+                rest)
+          (setq val (cdr val)))
+        (while defaults
+          (push `(const ,(pop defaults)) rest))
+        (widget-convert
+         'list
+         `(set :inline t :format "%v" ,@(nreverse rest))
+         `(repeat :inline t :tag "Other options"
+                  (cons :format "%v"
+                        (symbol :size 3 :format "(%v")
+                        (symbol :size 3 :format " . %v)\n")))))))
   :version "22.1" ;; Gnus 5.10.9
   :group 'mime)
 
diff --git a/lisp/gnus/rfc2047.el b/lisp/gnus/rfc2047.el
index ea5274798be..fb1c3606ed5 100644
--- a/lisp/gnus/rfc2047.el
+++ b/lisp/gnus/rfc2047.el
@@ -902,9 +902,13 @@ them.")
             (error
              (goto-char beg))))))))
 
-(defun rfc2047-charset-to-coding-system (charset)
+(defun rfc2047-charset-to-coding-system (charset &optional allow-override)
   "Return coding-system corresponding to MIME CHARSET.
-If your Emacs implementation can't decode CHARSET, return nil."
+If your Emacs implementation can't decode CHARSET, return nil.
+
+If allow-override is given, use `mm-charset-override-alist' to
+map undesired charset names to their replacement.  This should
+only be used for decoding, not for encoding."
   (when (stringp charset)
     (setq charset (intern (downcase charset))))
   (when (or (not charset)
@@ -912,7 +916,7 @@ If your Emacs implementation can't decode CHARSET, return nil."
             (memq 'gnus-all mail-parse-ignored-charsets)
             (memq charset mail-parse-ignored-charsets))
     (setq charset mail-parse-charset))
-  (let ((cs (mm-charset-to-coding-system charset)))
+  (let ((cs (mm-charset-to-coding-system charset nil allow-override)))
     (cond ((eq cs 'ascii)
            (setq cs (or (mm-charset-to-coding-system mail-parse-charset)
                         'raw-text)))
@@ -933,7 +937,7 @@ ENCODED-WORD)."
     (while words
       (setq word (pop words))
       (if (and (setq cs (rfc2047-charset-to-coding-system
-                         (setq charset (car word))))
+                         (setq charset (car word)) t))
                (condition-case code
                    (cond ((char-equal ?B (nth 1 word))
                           (setq text (base64-decode-string