anchor.diff:  
   (defun update-window (window-pane)
     (with-apply-in-pane-process-wait-single (window-pane)
  -    (multiple-value-bind (w h) (capi:simple-pane-visible-size window-pane)
  -      (when-let (pixmap (window-pane-pixmap window-pane)) (gp:destroy-pixmap-port pixmap))
  -      (setf (window-pane-pixmap window-pane) (gp:create-pixmap-port window-pane w h))
  -      (dolist (fn (nreverse (window-pane-drawing-queue window-pane)))
  -        (funcall fn (window-pane-pixmap window-pane)))
  -      (gp:copy-pixels window-pane (window-pane-pixmap window-pane) 0 0 w h 0 0)
  -      (setf (window-pane-drawing-queue window-pane) nil))))
  +    (dolist (fn (nreverse (window-pane-drawing-queue window-pane)))
  +      (funcall fn window-pane))
  +    (setf (window-pane-drawing-queue window-pane) nil)))
   
   (defun window-pane-display-callback (window-pane &rest args)
  -  (declare (ignore args))
  -  (with-error-handler ()
  -    (when (window-pane-pixmap window-pane)
  -      (multiple-value-bind (w h) (capi:simple-pane-visible-size window-pane)
  -        (gp:copy-pixels window-pane (window-pane-pixmap window-pane) 0 0 w h 0 0)))))
  +  (declare (ignore window-pane args)))
   
   (defun window-pane-resize-callback (window-pane &rest args)
     (declare (ignore args))
  
positive.code:              (char-height (+ (abs top) bottom)))
          (when reverse (rotatef foreground background))
          (with-drawing (window-pane)
            (gp:draw-rectangle window-pane
                               pixel-x
                               pixel-y
                               (* (lem:string-width string) char-width)
                               char-height
                               :foreground background
                               :filled t)
            (loop :with x1 := pixel-x :and y1 := (+ pixel-y char-height (- bottom))
                  :for c :across string
                  :do (gp:draw-character window-pane c x1 y1
                                         :font font
                                         :foreground foreground
                                         :background background
                                         :block t)
                      (incf x1 (* char-width (if (lem:wide-char-p c) 2 1)))
                  :finally (when underline
                             (gp:draw-line window-pane
                                           pixel-x
                                           (+ pixel-y char-height -4)
                                           x1
                                           (+ pixel-y char-height -4)
                                           :foreground foreground))))))))
  
  (defun %draw-string (window-pane string x y foreground background underline bold reverse)
    (update-font-if-required window-pane)
  
negative.code:         (lem-pane-resize-callback lem-pane)))))
  
  (defun destroy-window-pane (window-pane)
    (declare (ignore window-pane)))
  
  (defun change-font (window-pane family size)
    (let ((normal-font (gp:find-best-font
  