+ "Encode words in region B to E that need encoding.
+By default, the region is treated as containing RFC2822 addresses.
+Dynamically bind `rfc2047-encoding-type' to change that."
+ (save-restriction
+ (narrow-to-region b e)
+ (let ((encodable-regexp (if rfc2047-encode-encoded-words
+ "[^\000-\177]+\\|=\\?"
+ "[^\000-\177]+"))
+ start ; start of current token
+ end begin csyntax
+ ;; Whether there's an encoded word before the current token,
+ ;; either immediately or separated by space.
+ last-encoded
+ (orig-text (buffer-substring-no-properties b e)))
+ (if (eq 'mime rfc2047-encoding-type)
+ ;; Simple case. Continuous words in which all those contain
+ ;; non-ASCII characters are encoded collectively. Encoding
+ ;; ASCII words, including `Re:' used in Subject headers, is
+ ;; avoided for interoperability with non-MIME clients and
+ ;; for making it easy to find keywords.
+ (progn
+ (goto-char (point-min))
+ (while (progn (skip-chars-forward " \t\n")
+ (not (eobp)))
+ (setq start (point))
+ (while (and (looking-at "[ \t\n]*\\([^ \t\n]+\\)")
+ (progn
+ (setq end (match-end 0))
+ (re-search-forward encodable-regexp end t)))
+ (goto-char end))
+ (if (> (point) start)
+ (rfc2047-encode start (point))
+ (goto-char end))))
+ ;; `address-mime' case -- take care of quoted words, comments.
+ (with-syntax-table rfc2047-syntax-table
+ (goto-char (point-min))
+ (condition-case err ; in case of unbalanced quotes
+ ;; Look for rfc2822-style: sequences of atoms, quoted
+ ;; strings, specials, whitespace. (Specials mustn't be
+ ;; encoded.)
+ (while (not (eobp))
+ ;; Skip whitespace.
+ (skip-chars-forward " \t\n")
+ (setq start (point))
+ (cond
+ ((not (char-after))) ; eob
+ ;; else token start
+ ((eq ?\" (setq csyntax (char-syntax (char-after))))
+ ;; Quoted word.
+ (forward-sexp)
+ (setq end (point))
+ ;; Does it need encoding?
+ (goto-char start)
+ (if (re-search-forward encodable-regexp end 'move)
+ ;; It needs encoding. Strip the quotes first,
+ ;; since encoded words can't occur in quotes.
+ (progn
+ (goto-char end)
+ (delete-backward-char 1)
+ (goto-char start)
+ (delete-char 1)
+ (when last-encoded
+ ;; There was a preceding quoted word. We need
+ ;; to include any separating whitespace in this
+ ;; word to avoid it getting lost.
+ (skip-chars-backward " \t")
+ ;; A space is needed between the encoded words.
+ (insert ? )
+ (setq start (point)
+ end (1+ end)))
+ ;; Adjust the end position for the deleted quotes.
+ (rfc2047-encode start (- end 2))
+ (setq last-encoded t)) ; record that it was encoded
+ (setq last-encoded nil)))
+ ((eq ?. csyntax)
+ ;; Skip other delimiters, but record that they've
+ ;; potentially separated quoted words.
+ (forward-char)
+ (setq last-encoded nil))
+ ((eq ?\) csyntax)
+ (error "Unbalanced parentheses"))
+ ((eq ?\( csyntax)
+ ;; Look for the end of parentheses.
+ (forward-list)
+ ;; Encode text as an unstructured field.
+ (let ((rfc2047-encoding-type 'mime))
+ (rfc2047-encode-region (1+ start) (1- (point))))
+ (skip-chars-forward ")"))
+ (t ; normal token/whitespace sequence
+ ;; Find the end.
+ ;; Skip one ASCII word, or encode continuous words
+ ;; in which all those contain non-ASCII characters.
+ (setq end nil)
+ (while (not (or end (eobp)))
+ (when (looking-at "[\000-\177]+")
+ (setq begin (point)
+ end (match-end 0))
+ (when (progn
+ (while (and (or (re-search-forward
+ "[ \t\n]\\|\\Sw" end 'move)
+ (setq end nil))
+ (eq ?\\ (char-syntax (char-before))))
+ ;; Skip backslash-quoted characters.
+ (forward-char))
+ end)
+ (setq end (match-beginning 0))
+ (if rfc2047-encode-encoded-words
+ (progn
+ (goto-char begin)
+ (when (search-forward "=?" end 'move)
+ (goto-char (match-beginning 0))
+ (setq end nil)))
+ (goto-char end))))
+ ;; Where the value nil of `end' means there may be
+ ;; text to have to be encoded following the point.
+ ;; Otherwise, the point reached to the end of ASCII
+ ;; words separated by whitespace or a special char.
+ (unless end
+ (when (looking-at encodable-regexp)
+ (goto-char (setq begin (match-end 0)))
+ (while (and (looking-at "[ \t\n]+\\([^ \t\n]+\\)")
+ (setq end (match-end 0))
+ (progn
+ (while (re-search-forward
+ encodable-regexp end t))
+ (< begin (point)))
+ (goto-char begin)
+ (or (not (re-search-forward "\\Sw" end t))
+ (progn
+ (goto-char (match-beginning 0))
+ nil)))
+ (goto-char end))
+ (when (looking-at "[^ \t\n]+")
+ (setq end (match-end 0))
+ (if (re-search-forward "\\Sw+" end t)
+ ;; There are special characters better
+ ;; to be encoded so that MTAs may parse
+ ;; them safely.
+ (cond ((= end (point)))
+ ((looking-at (concat "\\sw*\\("
+ encodable-regexp
+ "\\)"))
+ (setq end nil))
+ (t
+ (goto-char (1- (match-end 0)))
+ (unless (= (point) (match-beginning 0))
+ ;; Separate encodable text and
+ ;; delimiter.
+ (insert " "))))
+ (goto-char end)
+ (skip-chars-forward " \t\n")
+ (if (and (looking-at "[^ \t\n]+")
+ (string-match encodable-regexp
+ (match-string 0)))
+ (setq end nil)
+ (goto-char end)))))))
+ (skip-chars-backward " \t\n")
+ (setq end (point))
+ (goto-char start)
+ (if (re-search-forward encodable-regexp end 'move)
+ (progn
+ (unless (memq (char-before start) '(nil ?\t ? ))
+ (if (progn
+ (goto-char start)
+ (skip-chars-backward "^ \t\n")
+ (and (looking-at "\\Sw+")
+ (= (match-end 0) start)))
+ ;; Also encode bogus delimiters.
+ (setq start (point))
+ ;; Separate encodable text and delimiter.
+ (goto-char start)
+ (insert " ")
+ (setq start (1+ start)
+ end (1+ end))))
+ (rfc2047-encode start end)
+ (setq last-encoded t))
+ (setq last-encoded nil)))))
+ (error
+ (if (or debug-on-quit debug-on-error)
+ (signal (car err) (cdr err))
+ (error "Invalid data for rfc2047 encoding: %s"
+ (mm-replace-in-string orig-text "[ \t\n]+" " "))))))))
+ (rfc2047-fold-region b (point))
+ (goto-char (point-max))))