[Dovecot] sieve 0.1.14: vacation encodes Subject twice

[Roland Rosenfeld]

Hi!

I noticed the following problem in dovecot-1.2-sieve-0.1.14:
The following vacation causes trouble with the Subject line:

if not exists ["List-Id", "List-Post"]  { 
    vacation :days 7 :addresses ["test at netcologne.de"] :subject "=?utf-8?b?w4TDlsOc?= sadasd" "Bin gerade nicht hier.";
} 

As you can see, the Subject is already MIME encoded according to
RFC2047.

Starting with sieve 0.1.14 the subject is now encoded by sieve again,
so I get the following in my vacation mail:

Subject: =?utf-8?q?=3D=3Futf-8=3Fb=3Fw4TDlsOc=3F=3D?= sadasd

As you can see, the RFC2047 encoding is RFC2047 encoded, which results
in an unreadable subject.

According to RFC5230 section 4.3 this shouldn't happen:

   The ":subject" parameter specifies a subject line to attach to any
   vacation response that is generated.  UTF-8 characters can be used in
   the string argument; implementations MUST convert the string to
   [RFC2047] encoded words if and only if non-ASCII characters are
   present.  Implementations MUST generate an appropriate default
   subject line as specified below if no :subject parameter is
   specified.

If I understand this right, sieve should do the RFC2047 encoding only
if the string is non-ASCII.  But the RFC2047 encoded string is already
ASCII, so it should not be encoded a second time.


I just compared this with sieve 0.1.13, which behaves different: It
does not encode the Subject header at all.  As long as the managesieve
client (in our situation Horde/IMP) encodes the subject, everything
works correct, while we run into trouble with 0.1.14.

I think that there needs to some mechanism in sieve that checks
whether the subject contains non-ASCII and does the encoding only in
this case.

I just checked out, that 0.1.14 does not encode a non RFC2047 encoded
7bit subject, while a 7bit subject starting with =?utf-8?... is
encoded twice.

Tschoeeee

        Roland

-- 
Roland Rosenfeld  -  Content Delivery  -  NED  -  Technik
NetCologne Gesellschaft für Telekommunikation mbH  -  HRB 25580, AG Köln
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