anchor.diff:    (declare (ignore predicate))
     (do-port-force-output eq))
   
  -;; STANDARD-SHEET-INPUT-MIXIN
  +;;; STANDARD-SHEET-INPUT-MIXIN
   
   (defclass standard-sheet-input-mixin ()
     ((queue :initform (make-instance 'port-event-queue)
  
positive.code: 		 (not (null (event-queue-head eq)))))
  	  (cond
  	    (timeout
  	     (loop as    timeout-time = (+ now timeout)
  		with  now = (now)
  		do    (when (pred)
  			(return t))
  		do    (when (>= now timeout-time)
  			(return nil))
  		do    (let ((timeout (if schedule-time
  					 (min (- schedule-time now)
  					      (- timeout-time now))
  					 (- timeout-time now))))
  			(condition-wait (event-queue-processes eq)
  					lock timeout))
  		do    (check-schedule eq)))
  	    (schedule-time
  	     (loop do (when (pred)
  			(return t))
  		do (condition-wait
  		    (event-queue-processes eq) lock (- schedule-time (now)))
  		do (check-schedule eq)))
  	    (t
  	     (or (pred)
  		 (progn
  
negative.code:                                 :sheet     (event-sheet item)
                                  :region    region)))
                            (setf (event-queue-tail eq) (cons item nil)) )
                           ((and (typep (car xs) 'window-repaint-event)
                                 (eq (event-sheet (car xs)) sheet))
                            ;; This is a repaint event for the same
                            ;; sheet, delete it and combine its region
                            ;; into the new event.
                            (setf region
                              (region-union region
  					  (window-event-native-region (car xs))))
                            ;; Here is an alternative, which just takes
                            ;; the bounding rectangle.
                            ;; NOTE: When doing this also take care that
                            ;; the new region really is cleared.
                            ;; (setf region
                            ;;   (let ((old-region (window-event-native-region (car xs))))
                            ;;     (make-rectangle*
  