anchor.diff:                     (previous-char previous-char)
                      (external-format external-format)
                      (encapsulated-stream encapsulated-stream)) stream
  +    (when (member char '(#\Newline #\Space))
  +      ;; Finish non-ASCII quoting
  +      (when line-has-non-ascii
  +        (format encapsulated-stream "?=")
  +        (setf line-has-non-ascii nil)))
       (cond
         ;; Newline processing
         ((eql char #\Newline)
  -       ;; Finish quoting
  -       (when line-has-non-ascii
  -         (format encapsulated-stream "?=")
  -         (setf line-has-non-ascii nil))
          ;; Print CR
          (write-char #\Return encapsulated-stream)
          ;; Test for end of header
  
positive.code:           (write-sequence sequence (encapsulated-stream stream)
                            :start start
                            :end end)
            (return))))))
negative.code:        (loop for byte across (flex:string-to-octets (make-string 1 :initial-element char)
                                                      :external-format external-format)
            do (format encapsulated-stream "=~2,'0X" byte))))
        (unless (eql #\Return char)
          (setf previous-char char))
        (unless (< 127 (char-code char))
  