[Dovecot] segfault in RC15

[Cor Bosman]

> >Dec 10 18:55:44 dovecot2.xs4all.nl dovecot: IMAP(XXX): Corrupted  
> >Index file /var/run/dovecot-index/l/ld/XXX/.INBOX/dovecot.index:  
> >Record [27].uid=0
> 
> Have you tried yet if rc17 fixes these?

Hi Timo, as I said before, they're not fixed. I dont get coredumps
anymore which makes this very hard for me to debug. As we noticed
before, the index files seem fine (you checked that). Would it be
possible to make a patch that doesnt copy the files, but dumps the
in-memory index someplace? It must be something very unlikely, as I
see this on a tiny fraction of our connections. Something like 1 in
every 100000. Could it be some race condition on the lock file, and
a second process reads a partial index? 

Cor