instead of the obsolete before-change-function and after-change-function.
appropriate for reading truly binary files.
** Code that relies on the obsolete `before-change-function' and
-`after-change-function' to detect buffer changes will now fail.
+`after-change-function' to detect buffer changes will now fail. Use
+`before-change-functions' and `after-change-functions' instead.
** Code that uses `concat' with integer args now gets an error, as
long promised.