'notmuch search thread:<>' lists multiple threads

[Naveen N. Rao]

David Bremner wrote:
> David Bremner <david at tethera.net> writes:
> 
>> At least some of this mail data is public, but I'm not sure if the bad
>> threading is reproducible or not; I want to run a complete census
>> overnight before I reindex.
>>
>> Even if the bug is non-deterministic, it probably lives in lib/add-message.cc
> 
> I have a reproducible test for this bug now
> 
>   http://pivot.cs.unb.ca/git?p=notmuch.git;a=shortlog;h=refs/heads/fix/thread-search

Thanks for looking into this.

> 
> I still need to analyze the mails a bit more, but it looks like at least
> one of the strange results is caused by multiple mail files sharing the
> same message-id, but with different References headers (and no
> In-Reply-To headers).

In my case, I seem to be having the In-Reply-To headers. I end up with 
two files per message: one from my inbox and one from the gmane archive 
that I pull in. All the messages from the gmane archive seem to have a 
re-written 'In-Reply-To' header, but 'Message-Id' and 'References' are 
the same.

In the problematic email thread, all other files/messages get allotted a 
single thread except for one of the messages. The offending message has 
3 references compared to 1 or 2 references for the rest, but I don't 
know if that's relevant here.

- Naveen