anchor.diff:    (multiple-value-bind (str win)
         (prev-history *minibuf-read-line-history*)
       (when win
  -      (buffer-erase)
  +      (minibuffer-clear-input)
         (insert-string str))))
   
   (define-command minibuf-read-line-next-history () ()
     (multiple-value-bind (str win)
         (next-history *minibuf-read-line-history*)
       (when win
  -      (buffer-erase)
  +      (minibuffer-clear-input)
         (insert-string str))))
   
   (define-command minibuf-read-line-break () ()
  
positive.code:                     (window-point (minibuffer-window)))
                     (*minibuf-read-line-depth*
                      (1+ *minibuf-read-line-depth*)))
                 (buffer-erase)
                 (minibuffer-mode)
                 (insert-string prompt)
                 (let ((*minibuffer-start-point* (current-point)))
                   (when initial
                   (insert-string initial))
                   (unwind-protect (call-with-save-windows
                                    (minibuffer-calls-window)
                                    (lambda ()
                                      (minibuf-read-line-loop prompt comp-f existing-p)))
                     (with-current-window (minibuffer-window)
                       (buffer-erase)
                       (insert-string minibuf-buffer-prev-string)
                       (point-set minibuf-buffer-prev-point))))))))
        (editor-abort (c)
  
negative.code:                       (minibuf-point-charpos)
                        (1- (minibuf-point-linum))))
  
  (defun minibuf-read-line-loop (comp-f existing-p)
    (let ((*minibuf-read-line-existing-p* existing-p)
          (*minibuf-read-line-comp-f* comp-f))
      (catch 'minibuf-read-line-end
  