[imp] Crashes when sorting by thread

[Chris Hastie]

A while ago I posted something here about problems I was having with 
Apache exiting on signal 11 whenever I tried to sort a folder by thread.

It was suggested I checked that my cclient was up-to-date, which it was. 
I now have a little more information on this, having just installed the 
CVS HEAD branch and given it another try.

The problem seems to be server specific. I can sort a folder by thread 
fine with Cyrus IMAPD (2.0.16). When I try to do the same with the 
rather obscure Turnpike 6.02 I see apache crashing. It may be worth 
noting that if a folder is empty I can sort on thread without problem, 
but that is not much use :).

If it is any help to any one I have a debug log of the IMAP exchange 
seen from Turnpike's perspective which you're welcome to have a look at. 
I've never managed to get my head around the IMAP protocol, but it looks 
to me as if Turnpike may not be returning the References for some 
reason. But even if there is a problem with the information Turnpike is 
sending, I'd have though Horde/Imp should cope with this rather more 
elegantly than having Apache exit on signal 11.

One other thing I notice in the IMAP log is that References and 
Followup-To appear to be requested, but not In-Reply-To, which is fairly 
widely used in mail.
-- 
Chris Hastie