anchor.diff:    "Recursively applies the function FN to all files within the
   directory named by the FILE-PATH designator DIRNAME and all of
   the files and directories contained within.  Returns T on success."
  -  (let* ((directory (file-path directory))
  -         (ns (file-path-namestring directory))
  -         (follow-inner-links
  -          (and follow-symlinks (not (eql :target follow-symlinks)))))
  +  (let ((follow-inner-links
  +         (and follow-symlinks (not (eql :target follow-symlinks)))))
       (labels ((walk (name depth parent)
                  (incf depth)
                  (let* ((kind
  
positive.code:                                    parent)))
                         name)))
        (handler-case
            (let ((kind
                   (file-kind directory :follow-symlinks follow-symlinks)))
              (unless (eq :directory kind)
                (isys:syscall-error "~S is not a directory" directory))
              (walk ns -1 ()) t)
  
negative.code:                       (ecase order
                          (:directory-first
                           (when (<= mindepth depth)
                             (funcall fn name-key kind))
                           (walkdir name depth parent))
                          (:depth-first
                           (walkdir name depth parent)
                           (when (<= mindepth depth)
                             (funcall fn name-key kind))))))
                     (t (when (and (funcall test name-key)
                                   (<= mindepth depth))
                          (funcall fn name-key)))))
  