gnus-summary-refer-thread does not find all

[Stefan Monnier]

I often find that A T doesn't find all the articles I'm looking for.
It turns out that one of the reason might be the following:

gnus-summary-limit-include-thread calls
gnus-summary-limit-include-matching-articles with "subject" and
a subject-regexp in decoded form (with non-ASCII chars).  These args are
then passed to gnus-find-matching-articles which compares uses the regexp on
the output of mail-header-subject but this output is not decoded (accented
chars are represented by sequences of other chars).


        Stefan