[Dovecot] Assertion failed

[Jonathan Knight]

Timo Sirainen wrote:
> On Tue, 2006-05-02 at 12:48 +0100, Jonathan Knight wrote:
>   
>> May  2 12:39:00 lenny dovecot: IMAP(XXXXX): file mbox-sync-rewrite.c: 
>> line 106 (mbox_sync_headers_add_space): assertion failed: (start_pos < 
>> data_size)
>>     
>
> Hmm. Does attached patch help?
>   


Sorry folks - I was testing out the bug with my own mailbox so I was 
offline for a moment or two.

I had a flash of inspiration which has identified the cause of the 
problem.  Due to an earlier mistake (not mine!) we ended up with the 
students having two copies of most of their mail messages.  The bug is 
triggered by trying to delete one of the duplicates.  Once the index 
files are mangled there is no way back other than deleting the index 
files and starting again.

I can only assume that the index code assumes that there is a unique 
identifier in a mail message and doesn't allow for a complete duplicate 
of a message being in a mailbox.

We didn't spot this during out test phase because we actually messed up 
the students mailboxes as we deployed new servers with dovecot installed.

I've written some perl to fix the mailboxes, but this should probably be 
addressed as it is possible to copy mail messages between folders and 
end up with a duplicate so I imagine that others will find the problem, 
although not on the scale that we did.

-- 
  ______    J.Knight at kis.keele.ac.uk     Jonathan Knight,
    /                                    Keele Information Services
   / _   __ Telephone: +44 1782 583478   University of Keele, Keele,
(_/ (_) / / Fax      : +44 1782 713082   Staffordshire.  ST5 5BG.  U.K.