anchor.diff:        (when (and header-start
                    (< header-start header-break))
           (if get-previous-line
  -            (let ((previous-line-pos (or (search #(13 10) bytes :end2 (- header-start 2) :from-end t) 0)))
  +            (let ((previous-line-pos (or (search
  +                                          (the simple-byte-vector
  +                                               #.(make-array 2
  +                                                         :element-type '(unsigned-byte 8)
  +                                                         :initial-contents '(13 10)))
  +                                          bytes :end2 (- header-start 2) :from-end t) 0)))
                 (subseq bytes (find-non-whitespace-pos bytes :start previous-line-pos)
                         header-break))
               (subseq bytes header-start header-break))))))
  
positive.code:         (chunk-start 0)
          (data-length (length data))
          (chunk-data (make-array 0 :element-type '(unsigned-byte 8)))
          (search-line-end  (make-array 2 :element-type '(unsigned-byte 8) :initial-contents #(13 10))))
      ;; loop over all available chunks until we get a partial
      (loop while (not (= last-chunk-start chunk-start)) do
        (setf last-chunk-start chunk-start)
  
negative.code:   ;; search for the telltale \r\n\r\n that marks the end of the headers
    (declare (type simple-byte-vector bytes)
             (optimize (speed 3) (safety 0)))
    (let ((header-break (search #.(make-array 4
                                            :element-type '(unsigned-byte 8)
                                            :initial-contents '(13 10 13 10))
                                bytes)))
      (unless header-break
        (return-from get-header-block))
      (let ((header-start (cl-irregsexp:if-match-bind
  