2.1.6B4: encode_ascii_prefixes error

[Werk21]

Hi!

Mailman seems not to encode the subject prefix
correctly.

Options:
Language: german (iso-8859-1)
encode_ascii_prefixes: Always
Prefix: ÄÖÜ
my mailsubject: äöü

result:
=?utf-8?b?W8OEw7bDnF0=?= =?iso-8859-1?q?
=E4=F6=FC?=

my Mailsubject: test

result:
=?utf-8?b?W8OEw7bDnF0=?= test

Mailman seems to convert always in utf regardless of
which language is chosen. The result is a subject-line
with two different encodings if you have special chars in
prefix and the subject-line.

A lot of mailcleints do not support this so that in the
display (not in the mailheader) the subject after the
prefix is lost.
And the space between prefix and subject will be lost
because it is not encoded.

This problem we did not have before using mailman
version 2.2a.

The MTA is postfix. I dont know if postfix is doing this
encoding to utf or mailman. In this case mailman fails to
convert the prefix.

If I choose
encode_ascii_prefixes: Needed
I get the same result.

If I choose
encode_ascii_prefixes: Never
I get the same result.

[http://sourceforge.net/tracker/index.php?func=detail&aid=1178199&group_id=103&atid=100103]