mail-extract-address-components fails on unqualified usernames

[Matt Swift]

This bug report will be sent to the Free Software Foundation,
 not to your local site managers!!
Please write in English, because the Emacs maintainers do not have
translators to read other languages for them.

In GNU Emacs 20.7.2 (i386-debian-linux-gnu, X toolkit)
 of Tue Jul 25 2000 on raven
configured using `configure  i386-debian-linux-gnu --prefix=/usr 
--sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib 
--infodir=/usr/share/info --with-pop=yes --with-x=yes --with-x-toolkit=yes'

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

(insert (princ (format "\n%S" (mail-extract-address-components "sam, george, 
louie" t))))
  ->  ((nil "sam") (nil "sam george") (nil "sam george louie"))

This is incorrect.  It seems to work fine whenever there is an "@" in the
addresses.  Compare:

(insert (princ (format "\n%S" (rfc822-addresses "sam, george, louie"))))
  ->  ("sam" "george" "louie")


from mail-extr.el:

;; This code is more correct (and more heuristic) parser than the code in
;; rfc822.el.  And despite its size, it's fairly fast.

Hmm....


Recent input:
C-p C-n M-f M-f M-f C-f C-f \ n M-q C-/ M-f M-f M-f 
M-f M-f M-f M-f M-f M-f M-f M-f M-f M-f M-b C-b C-b 
C-k C-x C-e C-p M-b M-b M-b M-b M-b M-f @ a c s C-n 
C-p C-e C-k C-k C-x C-e C-p M-b M-b M-b M-b M-b backspace 
C-d C-d C-d M-f M-f M-b M-d M-d M-d backspace backspace 
C-e C-x C-e C-k C-k C-k C-o C-o C-a C-p C-SPC C-n C-n 
M-w M-x r e p o r t - e m a c s - b u f backspace g 
return

Recent messages:
Undo!
((nil "sam") (nil "sam george") (nil "sam george louie") (nil "sam george louie 
bart@aol.com"))nil
Undo!

((nil "sam") (nil "sam george") (nil "sam george louie") (nil "sam george louie 
bart@aol.com"))nil

((nil "sam") (nil "sam george@acs") (nil "sam george louie") (nil "sam george 
louie bart@aol.com"))nil

((nil "sam") (nil "sam george") (nil "sam george louie"))nil
Mark set
None