anchor.diff:  (defvar *minibuf-read-line-tmp-window*)
   
   (defvar *minibuf-read-line-prompt*)
  -(defvar *minibuf-read-line-loop*)
   (defvar *minibuf-read-line-comp-f*)
   (defvar *minibuf-read-line-existing-p*)
   
  
positive.code:                         0)))
  
  (defun minibuf-read-line-loop (prompt comp-f existing-p)
    (let ((*minibuf-read-line-loop* t)
          (*minibuf-read-line-prompt* prompt)
          (*minibuf-read-line-existing-p* existing-p)
          (*minibuf-read-line-comp-f* comp-f))
      (do ((*curr-flags* (make-flags) (make-flags))
           (*last-flags* (make-flags) *curr-flags*))
          ((not *minibuf-read-line-loop*)
           (let ((str (minibuf-get-line)))
             (add-history *minibuf-read-line-history* str)
             str))
        (redraw-display)
        (let* ((key (read-key-sequence))
               (cmd (find-keybind key)))
          (handler-case (cmd-call cmd nil)
            (editor-abort (c)
              (when (/= (editor-abort-depth c)
                        *minibuf-read-line-depth*)
                (error c)))
            (editor-error (c) (message (editor-error-message c))))))))
  
  (defun minibuf-read-line (prompt initial comp-f existing-p)
    (let ((*minibuf-read-line-tmp-window* (current-window)))
  
negative.code:     (when (or (string= str "")
                (null *minibuf-read-line-existing-p*)
                (funcall *minibuf-read-line-existing-p* str))
        (throw 'minibuf-read-line-end t)))
    t)
  
  (define-command minibuf-read-line-completion () ()
  