anchor.diff:  if stuff is inserted after the insertion pointer."
     (assert (<= (input-position stream) (stream-scan-pointer stream)))
     (let* ((drei (drei-instance stream))
  +         (buffer (buffer (view drei)))
            (*command-processor* drei)
            (was-directly-processing (directly-processing-p drei))
  -         (*drei-input-editing-stream* stream))
  +         (*drei-input-editing-stream* stream)
  +         (old-buffer-contents (buffer-sequence buffer 0 (size buffer))))
       (with-bound-drei-special-variables (drei :prompt "M-x ")
         (update-drei-buffer stream)
         ;; Commands are permitted to signal immediate rescans, but
  
positive.code:                        (when was-directly-processing
                           (display-message "Aborted")))))))
          (update-drei-buffer stream))
        (let ((first-mismatch (when (plusp (prefix-size (view drei)))
                                (prefix-size (view drei)))))
          (display-drei drei :redisplay-minibuffer t)
          (cond ((null first-mismatch)
                 ;; No change actually took place, even though IP may
  
negative.code:              (drei-core:with-narrowed-buffer (drei
                                                (loop for index from
                                                      (1- (input-position stream)) above 0
                                                      when (typep (buffer-object buffer index)
                                                                  'noise-string)
                                                      return (1+ index)
                                                      finally (return 0))
  