Re: nnml splitting on encoded headers

[Mark Thomas <swoon@bellatlantic.net>]

Russ Allbery <rra@stanford.edu> writes:
>> Mark Thomas <swoon@bellatlantic.net> writes:
> 
>>> I have split rules:
>>>   ("subject"  "=\\?euc-kr\\?"          "mail.spam.asian")
>>>   ("subject"  "=\\?ks_c_5601-1987\\?"  "mail.spam.asian")
>>> but these don't to work because Gnus has already decoded the
>>> messages.

> Kai's right.  It does work; I use this all the time.  It isn't Gnus
> decoding that's stopping this from working, but is instead the fact
> that Gnus by default expects word boundaries on either side of the
> pattern so you have to add .* before and after.

Yes, these will never match because of the word boundary rule.  (I
don't normally use fancy splitting because I don't like that
restriction.  Unfortunately, gnus-summary-respool-trace doesn't tell
you which regexp matched if you don't use fancy splitting.  In trying
to figure out what was happening, I quickly translated my normal split
rules to fancy rules and I had missed this.)

However, Gnus decodes the headers before running the split rules.
Check out this ChangeLog entry:

    2002-01-26  Lars Magne Ingebrigtsen  <larsi@gnus.org>
    
    	* nnmail.el (nnmail-article-group): Decode headers before running
    	split rules over them.
    	(nnmail-mail-splitting-charset): New variable.

and this snippet of code from nnmail-article-group:

    	;; Decode MIME headers and charsets.
    	(let ((mail-parse-charset nnmail-mail-splitting-charset))
    	  (mail-decode-encoded-word-region (point-min) (point-max)))

Cheers,

-Mark