anchor.diff:  (defmethod rename-file ((self fs-directory) from to)
     (let ((from-path (full-path-for-file self from))
   	(to-path (full-path-for-file self to)))
  +    ;; RENAME-FILE uses the from-path to provide defaults for the
  +    ;; to-path.  This is terrible, just terrible:
  +    (when (null (pathname-type to-path))
  +      (setf to-path (make-pathname :type :unspecific :defaults to-path)))
       (cl:rename-file from-path to-path)))
   
   (defmethod modified-time ((self fs-directory) file)
  
positive.code: (defmethod open-input ((self fs-directory) file)
    (make-instance 'fs-index-input :path (full-path-for-file self file)))
  
  
  
  (defclass fs-index-output (buffered-index-output)
  
negative.code: 
  (defmethod initialize-instance :after ((self fs-index-output) &key path)
    (with-slots (file) self
      (setf file (open path
  		     :direction :output
  		     :element-type '(unsigned-byte 8)
  		     :if-exists :supersede))))
  
  (defmethod close :after ((self fs-index-output))
    (with-slots (file) self
  