anchor.diff:  (defun make-rhandle (&key rhandle tree key name)
     (let ((handle 
   	 (%make-rhandle :tree (or tree (rhandle-tree rhandle))
  -			:key (when rhandle
  +			:key (when (or (and rhandle (rhandle-key rhandle)) key)
   			       (concatenate 'string 
  -					    (rhandle-key rhandle)
  -					    (when (and (rhandle-key rhandle) key) "\\")
  +					    (when rhandle (rhandle-key rhandle))
  +					    (when (and rhandle (rhandle-key rhandle) key) "\\")
   					    key))
   			:name name)))
       (setf (rhandle-fh handle)
  
positive.code: ;;;; Copyright (c) Frank James 2015 <frank.a.james@gmail.com>
  ;;;; This code is licensed under the MIT license.
  
  ;; need CL-REGISTRY for this
  
  (defpackage #:nefarious.registry
    (:use #:cl #:nefarious #:cl-registry)
  
negative.code: (defun find-rhandle (provider h)
    (gethash h (simple-provider-handles provider)))
  
  (defun make-registry-provider (tree &optional key)
    (let ((mhandle (make-rhandle :tree tree :key key)))
      (let ((provider 
  	   (make-instance 'registry-provider
  			  :mount-handle mhandle)))
  