[Emacs-diffs] Changes to emacs/lisp/international/utf-7.el [lexbind]

[Miles Bader]

Index: emacs/lisp/international/utf-7.el
diff -c /dev/null emacs/lisp/international/utf-7.el:1.3.2.1
*** /dev/null   Tue Oct 14 19:39:36 2003
--- emacs/lisp/international/utf-7.el   Tue Oct 14 19:39:24 2003
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*** 0 ****
--- 1,141 ----
+ ;;; utf-7.el --- utf-7 coding system
+ 
+ ;; Copyright (C) 2003  Free Software Foundation, Inc.
+ 
+ ;; Author: Dave Love <address@hidden>
+ ;; Keywords: i18n, mail
+ 
+ ;; This file is free software; you can redistribute it and/or modify
+ ;; it under the terms of the GNU General Public License as published by
+ ;; the Free Software Foundation; either version 2, or (at your option)
+ ;; any later version.
+ 
+ ;; This file is distributed in the hope that it will be useful,
+ ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+ ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ ;; GNU General Public License for more details.
+ 
+ ;; You should have received a copy of the GNU General Public License
+ ;; along with GNU Emacs; see the file COPYING.  If not, write to
+ ;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ ;; Boston, MA 02111-1307, USA.
+ 
+ ;;; Commentary:
+ 
+ ;; Defines a coding system for UTF-7, defined in RFC 2152.  Non-ASCII
+ ;; segments are encoded as base64-encoded big endian UTF-16.  Also
+ ;; defines a variation required for IMAP (RFC 2060).
+ 
+ ;; The encoding and decoding was originally taken from Jon K Hellan's
+ ;; implementation in Gnus, but has been substantially re-done.
+ 
+ ;; This probably needs more attention.  In particular, it's not
+ ;; completely consistent with iconv's behaviour.  It's arguable
+ ;; whether the IMAP version should be a coding system since it's
+ ;; apparently only used for IMAP mailbox names, so it's commented out.
+ 
+ ;;; Code:
+ 
+ (make-coding-system
+  'utf-7 0 ?U
+  "UTF-7 encoding of Unicode (RFC 2152)"
+  nil
+  `((safe-chars . ,(coding-system-get 'utf-16be 'safe-chars))
+    (mime-charset . utf-7)
+    (pre-write-conversion . utf-7-pre-write-conversion)
+    (post-read-conversion . utf-7-post-read-conversion)))
+ 
+ ;; (make-coding-system
+ ;;  'utf-7-imap 0 ?u
+ ;;  "UTF-7 encoding of Unicode, IMAP version (RFC 2060)"
+ ;;  nil
+ ;;  `((safe-chars . ,(coding-system-get 'utf-16be 'safe-chars))
+ ;;    (pre-write-conversion . utf-7-imap-pre-write-conversion)
+ ;;    (post-read-conversion . utf-7-imap-post-read-conversion)))
+ 
+ (defun utf-7-decode (len imap)
+   "Decode LEN bytes of UTF-7 at point.
+ IMAP non-nil means use the IMAP version."
+   (save-excursion
+     (save-restriction
+       (narrow-to-region (point) (+ (point) len))
+       (let ((not-esc (if imap "^&" "^+"))
+           (skip-chars (if imap "A-Za-z0-9+," "A-Za-z0-9+/")))
+       (while (not (eobp))
+         (skip-chars-forward not-esc)
+         (unless (eobp)
+           (forward-char)
+           (let ((p (point))
+                 (run-length (skip-chars-forward skip-chars)))
+             (if (eq ?- (char-after))
+                 (delete-char 1))
+             (unless (= run-length 0)  ; encoded lone esc-char
+               (let ((pl (mod (- run-length) 4)))
+                 (insert-char ?= pl)
+                 (if imap
+                     (subst-char-in-region p (point) ?, ?/))
+                 (base64-decode-region p (point)))
+               (decode-coding-region p (point) 'utf-16be)
+               (save-excursion
+                 (goto-char p)
+                 (delete-backward-char 1)))))))
+       (- (point-max) (point-min)))))
+ 
+ (defun utf-7-post-read-conversion (len)
+   (utf-7-decode len nil))
+ 
+ ;; (defun utf-7-imap-post-read-conversion (len)
+ ;;   (utf-7-decode len t))
+ 
+ (defun utf-7-encode (from to imap)
+   "Encode bytes between FROM and TO to UTF-7.
+ ESC and SKIP-CHARS are adjusted for the normal and IMAP versions."
+   (let* ((old-buf (current-buffer))
+        (esc (if imap ?& ?+))
+        ;; These are characters which can be encoded asis.
+        (skip-chars (if imap
+                        "\t\n\r\x20-\x25\x27-\x7e" ; rfc2060 
+                      ;; This includes the rfc2152 optional set.
+                      ;; Perhaps it shouldn't (like iconv).
+                      "\t\n\r -*,-[]-}"))
+        (not-skip-chars (format "^%s%c" skip-chars esc)))
+     (set-buffer (generate-new-buffer " *temp*"))
+     (if (stringp from)
+       (insert from)
+       (insert-buffer-substring old-buf from to))
+     (goto-char (point-min))
+     (while (not (eobp))
+       (skip-chars-forward skip-chars)
+       (if (eq ?+ (char-after))
+         (progn (forward-char)
+                (insert ?-))
+       (unless (eobp)
+         (insert esc)
+         (let ((p (point)))
+           (skip-chars-forward not-skip-chars)
+           (save-restriction
+             ;; encode-coding-region doesn't preserve point
+             (narrow-to-region p (point))
+             (encode-coding-region p (point-max) 'utf-16be)
+             (base64-encode-region p (point-max))
+             (if imap
+                 (subst-char-in-region p (point-max) ?/ ?,))
+             (goto-char p)
+             ;; As I read the RFC, this isn't correct, but it's
+             ;; consistent with iconv, at least regarding `='.
+             (skip-chars-forward "^= \t\n")
+             (delete-region (point) (point-max))))
+         (unless (eobp)
+           (insert ?-)))))
+     nil))
+ 
+ (defun utf-7-pre-write-conversion (from to)
+   (utf-7-encode from to nil))
+ 
+ ;; (defun utf-7-imap-pre-write-conversion (from to)
+ ;;   (utf-7-encode from to t))
+ 
+ (provide 'utf-7)
+ 
+ ;;; arch-tag: 975ee403-90a4-4286-97d2-4ed1323f4ef9
+ ;;; utf-7.el ends here