Encoding of specials in From

Encoding of specials in From

[=?iso-8859-1?q?Lars_Magne, _Ing=E9brigtsen?=]

A user noted that the following seems to be invalid:
 
(rfc2047-encode-string "\"Mats, Löfdahl\" <xyzzy@chello.se>")
=> "=?iso-8859-1?q?Mats,_L=F6fdahl?= <xyzzy@chello.se>"

That's correct -- but not in address headers.  Quoth RFC2047: 

   Only a subset of the printable ASCII characters may be used in
   'encoded-text'.  Space and tab characters are not allowed, so that
   the beginning and end of an 'encoded-word' are obvious.  The "?"
   character is used within an 'encoded-word' to separate the various
   portions of the 'encoded-word' from one another, and thus cannot
   appear in the 'encoded-text' portion.  Other characters are also
   illegal in certain contexts.  For example, an 'encoded-word' in a
   'phrase' preceding an address in a From header field may not contain
   any of the "specials" defined in RFC 822.  Finally, certain other
   characters are disallowed in some contexts, to ensure reliability for
   messages that pass through internetwork mail gateways.

RFC2822:   

specials        =       "(" / ")" /     ; Special characters used in
                        "<" / ">" /     ;  other parts of the syntax
                        "[" / "]" /
                        ":" / ";" /
                        "@" / "\" /
                        "," / "." /
                        DQUOTE

I've tested this, and Gnus seems like it's doing the wrong thing.
Just look at the From header in this message.

rfc2047.el has code to deal with this, but, er, it doesn't seem like
it's doing the right thing for some reason or other...
                        
-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi@gnus.org * Lars Magne Ingebrigtsen