purpose of (provide 'hashtable-print-readable) in subr.el?

[Michael Heerdegen]

Hi,

This looks odd to me: subr.el end with these lines:

| ;; The following statement ought to be in print.c, but `provide' can't
| ;; be used there.
| ;; http://lists.gnu.org/archive/html/emacs-devel/2009-08/msg00236.html
| (when (hash-table-p (car (read-from-string
|                         (prin1-to-string (make-hash-table)))))
|   (provide 'hashtable-print-readable))

(Yes, I've read the mentioned thread in emacs-dev.)

What's the purpose of this `provide' call?  I've downloaded
emacs-23.4.tar.gz from ftp.gnu.org.  The only place where
hashtable-print-readable occurs in code (including C) is the above
occurrence in subr.el.  And I don't see any reason why third party code
should want to test for such a feature.  So, why is it provided at all?
Just curious...


Regards,

Michael.