[Emacs-diffs] Changes to emacs/lisp/gnus/utf7.el

[Miles Bader]

Index: emacs/lisp/gnus/utf7.el
diff -c emacs/lisp/gnus/utf7.el:1.3 emacs/lisp/gnus/utf7.el:1.4
*** emacs/lisp/gnus/utf7.el:1.3 Mon Sep  1 15:45:28 2003
--- emacs/lisp/gnus/utf7.el     Sat Sep  4 13:13:44 2004
***************
*** 1,7 ****
! ;;; utf7.el --- UTF-7 encoding/decoding for Emacs
! ;; Copyright (C) 1999, 2000 Free Software Foundation, Inc.
  
  ;; Author: Jon K Hellan <address@hidden>
  ;; Keywords: mail
  
  ;; This file is part of GNU Emacs.
--- 1,8 ----
! ;;; utf7.el --- UTF-7 encoding/decoding for Emacs   -*-coding: iso-8859-1;-*-
! ;; Copyright (C) 1999, 2000, 2003 Free Software Foundation, Inc.
  
  ;; Author: Jon K Hellan <address@hidden>
+ ;; Maintainer: address@hidden
  ;; Keywords: mail
  
  ;; This file is part of GNU Emacs.
***************
*** 22,58 ****
  ;; Boston, MA 02111-1307, USA.
  
  ;;; Commentary:
! ;;; UTF-7 - A Mail-Safe Transformation Format of Unicode - RFC 2152
! ;;; This is a transformation format of Unicode that contains only 7-bit
! ;;; ASCII octets and is intended to be readable by humans in the limiting
! ;;; case that the document consists of characters from the US-ASCII
! ;;; repertoire.
! ;;; In short, runs of characters outside US-ASCII are encoded as base64
! ;;; inside delimiters.
! ;;; A variation of UTF-7 is specified in IMAP 4rev1 (RFC 2060) as the way
! ;;; to represent characters outside US-ASCII in mailbox names in IMAP.
! ;;; This library supports both variants, but the IMAP variation was the
! ;;; reason I wrote it.
! ;;; The routines convert UTF-7 -> UTF-16 (16 bit encoding of Unicode)
! ;;; -> current character set, and vice versa.
! ;;; However, until Emacs supports Unicode, the only Emacs character set
! ;;; supported here is ISO-8859.1, which can trivially be converted to/from
! ;;; Unicode.
! ;;; When decoding results in a character outside the Emacs character set,
! ;;; an error is thrown.  It is up to the application to recover.
  
  ;;; Code:
  
  (require 'base64)
  (eval-when-compile (require 'cl))
  
! (defvar utf7-direct-encoding-chars " -%'-*,-[]-}"
    "Character ranges which do not need escaping in UTF-7.")
  
! (defvar utf7-imap-direct-encoding-chars
    (concat utf7-direct-encoding-chars "+\\~")
    "Character ranges which do not need escaping in the IMAP variant of UTF-7.")
  
  (defsubst utf7-imap-get-pad-length (len modulus)
    "Return required length of padding for IMAP modified base64 fragment."
    (mod (- len) modulus))
--- 23,91 ----
  ;; Boston, MA 02111-1307, USA.
  
  ;;; Commentary:
! 
! ;; UTF-7 - A Mail-Safe Transformation Format of Unicode - RFC 2152
! ;; This is a transformation format of Unicode that contains only 7-bit
! ;; ASCII octets and is intended to be readable by humans in the limiting
! ;; case that the document consists of characters from the US-ASCII
! ;; repertoire.
! ;; In short, runs of characters outside US-ASCII are encoded as base64
! ;; inside delimiters.
! ;; A variation of UTF-7 is specified in IMAP 4rev1 (RFC 2060) as the way
! ;; to represent characters outside US-ASCII in mailbox names in IMAP.
! ;; This library supports both variants, but the IMAP variation was the
! ;; reason I wrote it.
! ;; The routines convert UTF-7 -> UTF-16 (16 bit encoding of Unicode)
! ;; -> current character set, and vice versa.
! ;; However, until Emacs supports Unicode, the only Emacs character set
! ;; supported here is ISO-8859.1, which can trivially be converted to/from
! ;; Unicode.
! ;; When decoding results in a character outside the Emacs character set,
! ;; an error is thrown.  It is up to the application to recover.
! 
! ;; UTF-7 should be done by providing a coding system.  Mule-UCS does
! ;; already, but I don't know if it does the IMAP version and it's not
! ;; clear whether that should really be a coding system.  The UTF-16
! ;; part of the conversion can be done with coding systems available
! ;; with Mule-UCS or some versions of Emacs.  Unfortunately these were
! ;; done wrongly (regarding handling of byte-order marks and how the
! ;; variants were named), so we don't have a consistent name for the
! ;; necessary coding system.  The code below doesn't seem to DTRT
! ;; generally.  E.g.:
! ;;
! ;; (utf7-encode "a+£")
! ;;   => "a+ACsAow-"
! ;;
! ;; $ echo "a+£"|iconv -f iso-8859-1 -t utf-7
! ;; a+-+AKM
! ;;
! ;;  -- fx 
! 
  
  ;;; Code:
  
  (require 'base64)
  (eval-when-compile (require 'cl))
+ (require 'mm-util)
  
! (defconst utf7-direct-encoding-chars " -%'-*,-[]-}"
    "Character ranges which do not need escaping in UTF-7.")
  
! (defconst utf7-imap-direct-encoding-chars
    (concat utf7-direct-encoding-chars "+\\~")
    "Character ranges which do not need escaping in the IMAP variant of UTF-7.")
  
+ (defconst utf7-utf-16-coding-system
+   (cond ((mm-coding-system-p 'utf-16-be-no-signature) ; Mule-UCS
+        'utf-16-be-no-signature)
+       ((and (mm-coding-system-p 'utf-16-be) ; Emacs 21.4 (?), Emacs 22
+             ;; Avoid versions with BOM.
+             (= 2 (length (encode-coding-string "a" 'utf-16-be))))
+        'utf-16-be)
+       ((mm-coding-system-p 'utf-16-be-nosig) ; ?
+        'utf-16-be-nosig))
+   "Coding system which encodes big endian UTF-16 without a BOM signature.")
+ 
  (defsubst utf7-imap-get-pad-length (len modulus)
    "Return required length of padding for IMAP modified base64 fragment."
    (mod (- len) modulus))
***************
*** 64,73 ****
        (end (point-max)))
      (narrow-to-region start end)
      (goto-char start)
!     (let ((esc-char (if for-imap ?& ?+))
!         (direct-encoding-chars
!          (if for-imap utf7-imap-direct-encoding-chars
!            utf7-direct-encoding-chars)))
        (while (not (eobp))
        (skip-chars-forward direct-encoding-chars)
        (unless (eobp)
--- 97,107 ----
        (end (point-max)))
      (narrow-to-region start end)
      (goto-char start)
!     (let* ((esc-char (if for-imap ?& ?+))
!          (direct-encoding-chars
!           (if for-imap utf7-imap-direct-encoding-chars
!             utf7-direct-encoding-chars))
!          (not-direct-encoding-chars (concat "^" direct-encoding-chars)))
        (while (not (eobp))
        (skip-chars-forward direct-encoding-chars)
        (unless (eobp)
***************
*** 75,81 ****
          (let ((p (point))
                (fc (following-char))
                (run-length
!                (skip-chars-forward (concat "^" direct-encoding-chars))))
            (if (and (= fc esc-char)
                     (= run-length 1))  ; Lone esc-char?
                (delete-backward-char 1) ; Now there's one too many
--- 109,115 ----
          (let ((p (point))
                (fc (following-char))
                (run-length
!                (skip-chars-forward not-direct-encoding-chars)))
            (if (and (= fc esc-char)
                     (= run-length 1))  ; Lone esc-char?
                (delete-backward-char 1) ; Now there's one too many
***************
*** 88,94 ****
    (save-restriction
      (narrow-to-region start end)
      (funcall (utf7-get-u16char-converter 'to-utf-16))
!     (base64-encode-region start (point-max))
      (goto-char start)
      (let ((pm (point-max)))
        (when for-imap
--- 122,129 ----
    (save-restriction
      (narrow-to-region start end)
      (funcall (utf7-get-u16char-converter 'to-utf-16))
!     (mm-with-unibyte-current-buffer
!       (base64-encode-region start (point-max)))
      (goto-char start)
      (let ((pm (point-max)))
        (when for-imap
***************
*** 135,149 ****
  
  (defun utf7-get-u16char-converter (which-way)
    "Return a function to convert between UTF-16 and current character set."
!   ;; Add test to check if we are really Latin-1.
!   ;; Support other character sets once Emacs groks Unicode.
!   (if (eq which-way 'to-utf-16)
!       'utf7-latin1-u16-char-converter
!     'utf7-u16-latin1-char-converter))
  
  (defun utf7-latin1-u16-char-converter ()
    "Convert latin 1 (ISO-8859.1) characters to 16 bit Unicode.
  Characters are converted to raw byte pairs in narrowed buffer."
    (goto-char (point-min))
    (while (not (eobp))
      (insert 0)
--- 170,193 ----
  
  (defun utf7-get-u16char-converter (which-way)
    "Return a function to convert between UTF-16 and current character set."
!   (if utf7-utf-16-coding-system
!       (if (eq which-way 'to-utf-16)
!         (lambda ()
!           (encode-coding-region (point-min) (point-max)
!                                 utf7-utf-16-coding-system))
!       (lambda ()
!         (decode-coding-region (point-min) (point-max)
!                               utf7-utf-16-coding-system)))
!     ;; Add test to check if we are really Latin-1.
!     (if (eq which-way 'to-utf-16)
!       'utf7-latin1-u16-char-converter
!       'utf7-u16-latin1-char-converter)))
  
  (defun utf7-latin1-u16-char-converter ()
    "Convert latin 1 (ISO-8859.1) characters to 16 bit Unicode.
  Characters are converted to raw byte pairs in narrowed buffer."
+   (mm-encode-coding-region (point-min) (point-max) 'iso-8859-1)
+   (mm-disable-multibyte)
    (goto-char (point-min))
    (while (not (eobp))
      (insert 0)
***************
*** 157,167 ****
      (if (= 0 (following-char))
        (delete-char 1)
        (error "Unable to convert from Unicode"))
!     (forward-char)))
  
  (defun utf7-encode (string &optional for-imap)
    "Encode UTF-7 STRING.  Use IMAP modification if FOR-IMAP is non-nil."
!   (let ((default-enable-multibyte-characters nil))
      (with-temp-buffer
        (insert string)
        (utf7-encode-internal for-imap)
--- 201,213 ----
      (if (= 0 (following-char))
        (delete-char 1)
        (error "Unable to convert from Unicode"))
!     (forward-char))
!   (mm-decode-coding-region (point-min) (point-max) 'iso-8859-1)
!   (mm-enable-multibyte))
  
  (defun utf7-encode (string &optional for-imap)
    "Encode UTF-7 STRING.  Use IMAP modification if FOR-IMAP is non-nil."
!   (let ((default-enable-multibyte-characters t))
      (with-temp-buffer
        (insert string)
        (utf7-encode-internal for-imap)
***************
*** 173,178 ****
--- 219,225 ----
      (with-temp-buffer
        (insert string)
        (utf7-decode-internal for-imap)
+       (mm-enable-multibyte)
        (buffer-string))))
  
  (provide 'utf7)