file-chase-links doesn't respect limit can be nil

[Christoph Conrad]

In GNU Emacs 21.3.50.20 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2003-04-09 on linux
configured using `configure '--with-x''

see part with ";;" below. if limit is nil max would raise an error.

(defun file-chase-links (filename &optional limit)
  "Chase links in FILENAME until a name that is not a link.
Unlike `file-truename', this does not check whether a parent
directory name is a symbolic link.
If the optional argument LIMIT is a number,
it means chase no more than that many links and then stop."
  (let (tem (newname filename)
            (count 0)
            ;; -cc- and added
            (max (and limit (max limit 100))))