Revert removal of `mm-hack-charsets' in Gnus

Revision: emacs@sv.gnu.org/emacs--devo--0--patch-1076

4 files changed, 83 insertions, 2 deletions

diff --git a/lisp/gnus/ChangeLog b/lisp/gnus/ChangeLog
index 8b65a32aed3..93151d1389e 100644
--- a/lisp/gnus/ChangeLog
+++ b/lisp/gnus/ChangeLog
@@ -1,3 +1,11 @@
+2008-02-24  Miles Bader  <miles@gnu.org>
+
+        * mm-util.el (mm-hack-charsets, mm-iso-8859-15-compatible)
+        (mm-iso-8859-x-to-15-table, mm-iso-8859-x-to-15-region)
+        (mm-find-mime-charset-region):
+        * mm-bodies.el (mm-encode-body):
+        * mml.el (mml-parse-1): Revert removal of `mm-hack-charsets'.
+
 2008-02-16  Reiner Steib  <Reiner.Steib@gmx.de>
 
         * mail-source.el (mail-source-delete-incoming): Change default.
diff --git a/lisp/gnus/mm-bodies.el b/lisp/gnus/mm-bodies.el
index be209a3e004..90d4acbdcd7 100644
--- a/lisp/gnus/mm-bodies.el
+++ b/lisp/gnus/mm-bodies.el
@@ -104,7 +104,8 @@ If no encoding was done, nil is returned."
                                      (mm-charset-to-coding-system charset))
             charset)
         (goto-char (point-min))
-        (let ((charsets (mm-find-mime-charset-region (point-min) (point-max))))
+        (let ((charsets (mm-find-mime-charset-region (point-min) (point-max)
+                                                     mm-hack-charsets)))
           (cond
            ;; No encoding.
            ((null charsets)
diff --git a/lisp/gnus/mm-util.el b/lisp/gnus/mm-util.el
index 2f473ff184c..8e625c936e4 100644
--- a/lisp/gnus/mm-util.el
+++ b/lisp/gnus/mm-util.el
@@ -576,6 +576,36 @@ with Mule charsets.  It is completely useless for Emacs."
           (push (cons mime (delq 'ascii mule)) alist)))
       (setq mm-mime-mule-charset-alist (nreverse alist)))))
 
+(defvar mm-hack-charsets '(iso-8859-15 iso-2022-jp-2)
+  "A list of special charsets.
+Valid elements include:
+`iso-8859-15'    convert ISO-8859-1, -9 to ISO-8859-15 if ISO-8859-15 exists.
+`iso-2022-jp-2'  convert ISO-2022-jp to ISO-2022-jp-2 if ISO-2022-jp-2 exists."
+)
+
+(defvar mm-iso-8859-15-compatible
+  '((iso-8859-1 "\xA4\xA6\xA8\xB4\xB8\xBC\xBD\xBE")
+    (iso-8859-9 "\xA4\xA6\xA8\xB4\xB8\xBC\xBD\xBE\xD0\xDD\xDE\xF0\xFD\xFE"))
+  "ISO-8859-15 exchangeable coding systems and inconvertible characters.")
+
+(defvar mm-iso-8859-x-to-15-table
+  (and (fboundp 'coding-system-p)
+       (mm-coding-system-p 'iso-8859-15)
+       (mapcar
+        (lambda (cs)
+          (if (mm-coding-system-p (car cs))
+              (let ((c (string-to-char
+                        (decode-coding-string "\341" (car cs)))))
+                (cons (char-charset c)
+                      (cons
+                       (- (string-to-char
+                           (decode-coding-string "\341" 'iso-8859-15)) c)
+                       (string-to-list (decode-coding-string (car (cdr cs))
+                                                             (car cs))))))
+            '(gnus-charset 0)))
+        mm-iso-8859-15-compatible))
+  "A table of the difference character between ISO-8859-X and ISO-8859-15.")
+
 (defcustom mm-coding-system-priorities
   (if (boundp 'current-language-environment)
       (let ((lang (symbol-value 'current-language-environment)))
@@ -829,6 +859,27 @@ This affects whether coding conversion should be attempted generally."
           default-enable-multibyte-characters
         t)))
 
+(defun mm-iso-8859-x-to-15-region (&optional b e)
+  (if (fboundp 'char-charset)
+      (let (charset item c inconvertible)
+        (save-restriction
+          (if e (narrow-to-region b e))
+          (goto-char (point-min))
+          (skip-chars-forward "\0-\177")
+          (while (not (eobp))
+            (cond
+             ((not (setq item (assq (char-charset (setq c (char-after)))
+                                    mm-iso-8859-x-to-15-table)))
+              (forward-char))
+             ((memq c (cdr (cdr item)))
+              (setq inconvertible t)
+              (forward-char))
+             (t
+              (insert-before-markers (prog1 (+ c (car (cdr item)))
+                                       (delete-char 1)))))
+            (skip-chars-forward "\0-\177")))
+        (not inconvertible))))
+
 (defun mm-sort-coding-systems-predicate (a b)
   (let ((priorities
          (mapcar (lambda (cs)
@@ -976,6 +1027,26 @@ charset, and a longer list means no appropriate charset."
                (mapcar 'mm-mime-charset
                        (delq 'ascii
                              (mm-find-charset-region b e))))))
+    (if (and (> (length charsets) 1)
+             (memq 'iso-8859-15 charsets)
+             (memq 'iso-8859-15 hack-charsets)
+             (save-excursion (mm-iso-8859-x-to-15-region b e)))
+        (dolist (x mm-iso-8859-15-compatible)
+          (setq charsets (delq (car x) charsets))))
+    (if (and (memq 'iso-2022-jp-2 charsets)
+             (memq 'iso-2022-jp-2 hack-charsets))
+        (setq charsets (delq 'iso-2022-jp charsets)))
+    ;; Attempt to reduce the number of charsets if utf-8 is available.
+    (if (and (featurep 'xemacs)
+             (> (length charsets) 1)
+             (mm-coding-system-p 'utf-8))
+        (let ((mm-coding-system-priorities
+               (cons 'utf-8 mm-coding-system-priorities)))
+          (setq charsets
+                (mm-delete-duplicates
+                 (mapcar 'mm-mime-charset
+                         (delq 'ascii
+                               (mm-find-charset-region b e)))))))
     charsets))
 
 (defmacro mm-with-unibyte-buffer (&rest forms)
diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index c335e985d0e..2b5987e5e6e 100644
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -284,7 +284,8 @@ part.  This is for the internal use, you should never modify the value.")
                          (list
                           (intern (downcase (cdr (assq 'charset tag))))))
                         (t
-                         (mm-find-mime-charset-region point (point)))))
+                         (mm-find-mime-charset-region point (point)
+                                                      mm-hack-charsets))))
         (when (and (not raw) (memq nil charsets))
           (if (or (memq 'unknown-encoding mml-confirmation-set)
                   (message-options-get 'unknown-encoding)