[Dovecot] MIME Decoding Problem

[Jim Rosenberg]

On Sun, Jan 20, 2008 at 02:42:45PM +0200, Timo Sirainen wrote:
> On Wed, 2007-12-12 at 09:09 -0500, Jim Rosenberg wrote:
> > I am having a recurring problem with Dovecot 1.0.8 failing to MIME-decode
> > certain messages. The client is Mulberry 4.0.8. The messages causing the
> > problem seem to be MIME messages with "no parts". I.e. the message has
> > some MIME encoding, but is just included as the message body. The kind of
> > effect I will see is a proliferation of untranslated =xx codes, or in
> > some cases an untranslated base64 block. I.e. I see the raw text from the
> > message body with no MIME decoding at all.
> 
> Does this still happen with v1.0.10?
> 

I just upgraded yesterday, and am still evaluating, but it looks like I have
bad news and good news. The bad news is that the situation is "worse"; the
good news is that I *think* (but am not certain yet) I have a reproducible
scenario for what triggers the problem.

What is happening now in Mulberry is that my folder window simply *dies*,
and in the dovecot log file I have messages like this: [grepped ...]

Jan 23 05:57:07 shrimp dovecot: child 1139 (imap) killed with signal 11
Jan 23 05:57:23 shrimp dovecot: child 13824 (imap) killed with signal 11
Jan 23 05:57:49 shrimp dovecot: child 27351 (imap) killed with signal 11
Jan 23 05:58:04 shrimp dovecot: child 12302 (imap) killed with signal 11
Jan 23 06:12:53 shrimp dovecot: child 16341 (imap) killed with signal 11
Jan 23 06:13:08 shrimp dovecot: child 127 (imap) killed with signal 11

Now for the interesting part. What I think is triggering this is that I have
a couple of Mulberry search rules that I don't use all the time that search
for an "and'ed" set of conditions, one of which is

The *entire message* contains <a string>

This seems to trigger a chache inconsistency in Dovecot. When the MIME
decoding problem was happening, I found I could clear the problem by closing
the folder window, deleting the .imap cache file on the server, and
reopening the window. That also works for the current symptom (folder window
dies).

This is still preliminary, but it looks to me at the moment like something
goes inconsistent in the cache when you search the entire contents of
messages rather than just headers. When I used my saved searches that only
use criteria based on headers, everything is fine.

-Thanks, Jim