[Dovecot] Hang in 1.0.alpha4

[Mark Plaksin]

My IMAP client hangs intermittently.  When it does, Dovecot has prematurely
stopped sending a response and entered the poll loop.  My client is waiting
for more data and Dovecot is waiting for an IMAP command.

This problem seems to occur when I connect to the dovecot process over
the network and when I run the imap binary directly via an SSH tunnel.

Below is truss output from the imap process for one of the hangs.  It is
responding to a FETCH, gets EAGAIN, and then seems to give up sending the
rest of the message and enters the poll loop.  Below that is the log from
my IMAP client to show its side of the story.

Nothing shows up in the normal Dovecot log.  I haven't caught it in the act
recently when running with rawlog.  But rawlog output from before I was
running with truss shows that Dovecot does not think it has finished sending
its response.

truss output:
12951:  stat64("/home/happy/Mail/banner-ss", 0xFFBFF200) = 0
12951:  fstat64(12, 0xFFBFF388)                         = 0
12951:  stat64("/home/happy/Mail/.imap/banner-ss/dovecot.index", 0xFFBFF2F0) = 0
12951:  fstat64(18, 0xFFBFF388)                         = 0
12951:  pread64(18, "\n F r o m   b e v e r l".., 4096, 1592560) = 4096
12951:  pread64(18, " S u n G a r d   *   S C".., 4094, 1596656) = 4094
12951:  pread64(18, " M i c r o s o f t   S a".., 4094, 1600750) = 4094
12951:  pread64(18, " r g a r e t . d i l l a".., 4094, 1604844) = 3720
12951:  pread64(18, 0x0025EEA2, 374, 1608564)           = 0
12951:  pread64(18, 0x0025EEA2, 374, 1608564)           = 0
12951:  pread64(18, " R e t u r n - P a t h :".., 4096, 1592616) = 4096
12951:  write(1, " *   2 5 0   F E T C H  ".., 4073)    = 4073
12951:  pread64(18, " a l v e r n ,   P A    ".., 4095, 1596712) = 4095
12951:  write(1, "\n W i l l i a m   B .  ".., 4060)    = 4060
12951:  pread64(18, " l   ( i n c l u d i n g".., 4095, 1600807) = 4095
12951:  write(1, "\n & # 8 2 2 6 ;   < / b".., 4069)    = 4069
12951:  pread64(18, " m o z - t x t - l i n k".., 4095, 1604902) = 3662
12951:  write(1, "\n                      ".., 4079)    Err#11 EAGAIN
12951:  write(1, "\n                      ".., 4096)    Err#11 EAGAIN
12951:  poll(0x000A0AD0, 3, 533)                        = 1
12951:  write(1, "\n                      ".., 4096)    = 4096
12951:  poll(0x000A0AD0, 2, 532)                        = 0
12951:  poll(0x000A0AD0, 2, 0)                          = 0
12951:  poll(0x000A0AD0, 2, 999)        (sleeping...)
12951:  poll(0x000A0AD0, 2, 999)                        = 0

Here's the log from my IMAP client.  I removed email addresses and most of
the body of the message to protect the innocent.  The "BYE" was caused by
me running 'kill $PID' on the imap process.

3551 OK Fetch completed.!
3552 UID FETCH 252 BODY.PEEK[]
* 250 FETCH (UID 252 BODY[] {16341}!
Return-Path: <abc at usg.edu>!
Received: from usg.edu (abc.usg.edu [1.2.8.1])!
	by abc.usg.edu (8.12.11/8.12.11) with ESMTP id j9KFqoga012884!
	for <abc at USG.EDU>; Thu, 20 Oct 2005 11:52:50 -0400 (EDT)!
Message-ID: <4357BD52.1020506 at usg.edu>!
Date: Thu, 20 Oct 2005 11:52:50 -0400!
From: abc <abc at usg.edu>!
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax)!
X-Accept-Language: en-us, en!
MIME-Version: 1.0!
To: abc at usg.edu!
Subject: [Fwd: [Fwd: Fw: Java Library Problem]] - URGENT, I'm sorry...!
Content-Type: multipart/mixed;!
 boundary="------------010604070704040405060605"!
X-USG-MailScanner: Found to be clean!
X-USG-MailScanner-SpamCheck: !
X-MailScanner-From: abc at usg.edu!
!
This is a multi-part message in MIME format.!
--------------010604070704040405060605!
Content-Type: multipart/alternative;!
 boundary="------------040009050704020209010709"!
!
!
--------------040009050704020209010709!
Content-Type: text/plain; charset=us-ascii; format=flowed!
Content-Transfer-Encoding: 7bit!
!
Guys,!
Please create a ssh login on... from !
24 hours now) with testing.    His account should look like Patrick !
I've requested a static IP from Dan.!
!
...!
</pre>!
</body>!
</html>!
!
--------------040009050704020209010709--!
!
--------------010604070704040405060605!
Content-Type: text/x-vcard;!
Content-Transfer-Encoding: 7bit!
Content-Disposition: attachment;!
!
begin:vcard!
...!
tel;work:(xxx) xxx-2000!
tel;fax:(xxx) xxx-xxxx!
url:http://www.u* BYE Server shutting down.!
imap(happy): Warning: Killed with signal 15

------------------------------------------------------------------------------
The mail message in question actually ends like this:

tel;work:(xxx) xxx-2000
tel;fax:(xxx) 583xxx-xxxx
url:http://www.usg.edu
version:2.1
end:vcard

--------------010604070704040405060605--