I was reading a newsgroup with Gnus, typed `n'
(gnus-summary-next-unread-article) to read the next article[1], and got
a wrong-type-argument error.  The backtrace is attached.  The error
occurs in rfc822-bad-address, when the first argument of
narrow-to-region, rfc822-address-start, is nil.  The value is nil at
this point because rfc822-addresses calls rfc822-nuke-whitespace before
rfc822-address-start is assigned an initial value.  Simply assigning an
initial non-nil in the let declaration does not work, because then
rfc822-bad-address tries to throw to 'address, but the corresponding
catch in rfc822-addresses has not yet been established -- that happens
after the call to rfc822-nuke-whitespace.  I tried moving the catch
above the rfc822-nuke-whitespace call: in combination with an initial
value for rfc822-address-start, this allows rfc822-bad-address to return
an error string to rfc822-addresses -- see the patch below --, but the
caller in my setup, bbdb-rfc822-addresses, expects a list, so this
raises another wrong-type-argument error.  If it is legitimate for
rfc822-bad-address to return a non-list value in this case, then the bug
is presumably in bbdb-rfc822-addresses (from bbdb-snarf.el, not part of
Emacs); but I don't know if this is the right diagnosis.  If it is, I'll
report it to the BBDB list, and the patch below, or a better one, should
be applied to rfc822.el.

Steve Berman