Recent change to file-chase-links has a bug

[Kenichi Handa]

This change has a bug.

2003-04-08  Richard M. Stallman  <address@hidden>
[...]
        * files.el (file-chase-links): New arg LIMIT.
        After that many iterations, just return what we've got.

Now the code is as below:

(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)
            (max (max limit 100)))
    (while (and (or (null limit) (< count limit))
                (setq tem (file-symlink-p newname)))
      (save-match-data
        (if (= count max)
            (error "Apparent cycle of symbolic links for %s" filename))

At least, (max limit 100) must be:
        (max (if (numberp limit) limit 0) 100)
Otherwise, for instance, C-x 4 a signals an error.

And, if the docstring is correct, actually the code must be
something like this:

(defun file-chase-links (filename &optional limit)
[...]
  (let (tem (newname filename)
            (count 0)
            (max 100)
    (while (and (or (not (numberp limit)) (< count limit))
                (setq tem (file-symlink-p newname)))
      (save-match-data
        (if (= count max)
            (error "Apparent cycle of symbolic links for %s" filename))

But, I have not yet installed that fix because it seems that
the original line "(max (max limit 100))" suggests some
other intention, e.g., "don't allow a limit less than 100".

---
Ken'ichi HANDA
address@hidden