anchor.diff:    ;; make sure the file actually exists before mapping it 
     (let ((path (ensure-file-exists path size)))
   
  -  (let ((fhandle (with-foreign-string (s path)
  -		   (%create-file s 
  -				 #xC0000000 ;; access == generic_read|generic_write
  -				 3 ;; mode == share_read|share_write
  -				 (null-pointer) ;; attrs
  -				 4 ;; disposition == open always
  -				 128 ;; flags == file attribute normal
  -				 (null-pointer)))))
  -    (when (invalid-handle-p fhandle)
  -      (get-last-error))
  -    
  -    (let ((mhandle (%create-file-mapping fhandle
  -					 (null-pointer) ;; attrs
  -					 4 ;; protect == page_readwrite
  -					 0 ;; high
  -					 0 ;; low
  -					 (null-pointer))))
  -      (when (null-pointer-p mhandle)
  -	(%close-handle fhandle)
  +    (let ((fhandle (with-foreign-string (s path)
  +		     (%create-file s 
  +				   #xC0000000 ;; access == generic_read|generic_write
  +				   3 ;; mode == share_read|share_write
  +				   (null-pointer) ;; attrs
  +				   4 ;; disposition == open always
  +				   128 ;; flags == file attribute normal
  +				   (null-pointer)))))
  +      (when (invalid-handle-p fhandle)
   	(get-last-error))
  -      (let ((ptr (%map-view-of-file mhandle
  -				    #x001f ;; access == filemapallaccess
  -				    0 ;; low
  -				    0 ;; high
  -				    size)))
  -	(when (null-pointer-p ptr)
  -	  (%close-handle mhandle)
  +      
  +      (let ((mhandle (%create-file-mapping fhandle
  +					   (null-pointer) ;; attrs
  +					   4 ;; protect == page_readwrite
  +					   0 ;; high
  +					   0 ;; low
  +					   (null-pointer))))
  +	(when (null-pointer-p mhandle)
   	  (%close-handle fhandle)
   	  (get-last-error))
  -	(make-mapping :fhandle fhandle
  -		      :mhandle mhandle
  -		      :ptr ptr
  -		      :size size))))))
  +	(let ((ptr (%map-view-of-file mhandle
  +				      #x001f ;; access == filemapallaccess
  +				      0 ;; low
  +				      0 ;; high
  +				      size)))
  +	  (when (null-pointer-p ptr)
  +	    (%close-handle mhandle)
  +	    (%close-handle fhandle)
  +	    (get-last-error))
  +	  (make-mapping :fhandle fhandle
  +			:mhandle mhandle
  +			:ptr ptr
  +			:size size))))))
   
   (defun close-mapping (mapping)
     "Closes the mapping structure."
  
positive.code: 		   overlapped)))
  
  (defun unlock-mapping (map)
    (with-foreign-object (overlapped '(:struct overlapped))
      (setf (foreign-slot-value overlapped '(:struct overlapped)
  			      'offset)
  
negative.code: 
  (defun remap (mapping size)
    "Remap the file. SIZE should be the new size."
    (declare (type mapping mapping)
  	   (type integer size))
    (%munmap (mapping-ptr mapping)
  	   (mapping-size mapping))
    ;; write a byte at size
  