21.1: copyright-regexp and (C)

[Kevin Ryde]

In GNU Emacs 21.1.1 (i386-debian-linux-gnu, X toolkit)
 of 2001-10-22 on raven, modified by Debian
configured using `configure  i386-debian-linux-gnu --prefix=/usr 
--sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib 
--infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes --with-x=yes 
--with-x-toolkit=yes'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: C
  locale-coding-system: nil
  default-enable-multibyte-characters: t


With a file foo.txt containing a single line,

        Copyright 2000, 2001 Foo Bar, Inc.

M-x copyright-update silently does nothing, whereas I hoped it would
add a 2002.

It seems copyright-regexp insists on having a "(C)" or a copyright
symbol character after the word "Copyright".  It'd be good if that was
only optional, since if I'm not mistaken the form above is recommended
by the GNU maintainer guidelines.