copyright-update-year broken in some modes

[Glenn Morris]

rev 1.58 of copyright.el breaks copyright-update-year in some modes,
eg texinfo, depending on the value of comment-start-skip:

emacs -Q man/calendar.texi
M-x copyright-update
Wrong type argument: integer-or-marker-p, nil

comment-start-skip does not contain any subexpressions in texinfo mode
(nor need it, according to the documentation), so the change from
(match-end 0) to (match-end 1) at line 114 of copyright.el causes
problems.


2007-05-25  Stefan Monnier  <address@hidden>

            * emacs-lisp/copyright.el (copyright-names-regexp): New var.
              (copyright-update-year): Use it.