font-lock and revert buffer.

The sccs I use has a locking model so files on disk are usually read-only but if you check them out they are unchanged (you get the same version you are looking at) but read-write. The emacs integration I use calls (revert-buffer t t) after checkout to get the file up to date, but this is an incredible amount of wasted work (and slow) because the whole buffer is fontified from scratch, JDE reparses the buffer, etc, etc - when actually the file is totally unchanged apart from the permissions. It seems like revert-buffer should recognize this as a special case and simply change the permissions etc in XEmacs. Anyone have any comments, opinions or suggestions on this? Does Emacs do anything different to us? Thanks andy