anchor.diff:  
   (defmethod window-active ((interface remote-interface))
     "Return the window object for the currently active window."
  -  ;; TODO: Maybe return last focused window instead of NIL if no window is
  -  ;; currently focused.  Currently, many functions fail when run, say, from the
  -  ;; REPL, if no window is focused.
  -  (with-slots (host port url windows) interface
  -    (gethash (s-xml-rpc:xml-rpc-call
  -              (s-xml-rpc:encode-xml-rpc-call "window.active")
  -              :host host :port port :url url)
  -             windows)))
  +  (with-slots (host port url windows) interface
  +    (let ((window (gethash (s-xml-rpc:xml-rpc-call
  +                            (s-xml-rpc:encode-xml-rpc-call "window.active")
  +                            :host host :port port :url url)
  +                           windows)))
  +      (when window
  +        (setf (last-active-window interface) window))
  +      (last-active-window interface))))
   
   (defmethod window-exists ((interface remote-interface) (window window))
     "Return if a window exists."
  
positive.code:   (active-buffer window))
  
  (defmethod window-set-minibuffer-height ((interface remote-interface)
                                           (window window) height)
    ;; WINDOW could be empty if, for instance, nothing window was focused when
    ;; calling WINDOW-ACTIVE.
    (when (and interface window (id window))
      (with-slots (host port url) interface
        (s-xml-rpc:xml-rpc-call
         (s-xml-rpc:encode-xml-rpc-call "window.set.minibuffer.height" (id window) height)
         :host host :port port :url url))))
  
  (defmethod buffer-make ((interface remote-interface))
    (with-slots (host port url buffers) interface
  
negative.code:    (port :accessor port :initform (getf *platform-port-socket* :port))
     (url :accessor url :initform "/RPC2")
     (windows :accessor windows :initform (make-hash-table :test #'equal))
     (last-active-window :accessor last-active-window :initform nil)
     (buffers :accessor buffers :initform (make-hash-table :test #'equal))))
  
  (defmethod start-interface ((interface remote-interface))
  