anchor.diff:  If a buffer is already visiting that file, switch to that
   buffer. Does not create a file if the filename given does not
   name an existing file."
  -  (find-file filepath))
  +  (handler-case (find-file filepath)
  +    (file-error (e)
  +      (display-message "~A" e))))
   
   (set-key `(com-find-file ,*unsupplied-argument-marker*)
            'esa-io-table '((#\x :control) (#\f :control)))
  
positive.code: 	t)))
  
  (defmethod frame-save-buffer (application-frame buffer)
    (handler-case
        (let ((filepath (or (filepath buffer)
                            (accept 'pathname :prompt "Save Buffer to File"))))
          (check-buffer-writability application-frame filepath buffer)
          (unless (check-file-times buffer filepath "Overwrite" "written")
            (return-from frame-save-buffer))
          (when (and (probe-file filepath) (not (file-saved-p buffer)))
            (let ((backup-name (pathname-name filepath))
                  (backup-type (format nil "~A~~~D~~"
                                       (pathname-type filepath)
                                       (1+ (version-number filepath)))))
              (rename-file filepath (make-pathname :name backup-name
                                                   :type backup-type))))
          (with-open-file (stream filepath :direction :output :if-exists :supersede)
            (save-buffer-to-stream buffer stream))
          (setf (filepath buffer) filepath
                (file-write-time buffer) (file-write-date filepath)
                (name buffer) (filepath-filename filepath))
          (display-message "Wrote: ~a" (filepath buffer))
          (setf (needs-saving buffer) nil))
      (file-error (c)
        (display-message "~A" c))))
  
  (define-command (com-save-buffer :name t :command-table esa-io-table) ()
    "Write the contents of the buffer to a file.
  
negative.code:                                             :default-type 'pathname))
          (if (needs-saving buffer)
              (handler-case (save-buffer buffer)
                ((or buffer-writing-error file-error) (e)
                  (display-message "~A" e)))
              (display-message "No changes need to be saved from ~a" (name buffer))))))
  
  (set-key 'com-save-buffer 'esa-io-table '((#\x :control) (#\s :control)))
  