[notmuch] Duplicate In-reply-to line 326 lib/message.cc

[David Bremner]

On the trail of a searching problem, I enabled debugging with 
   make CFLAGS="-g -DDEBUG" CXXFLAGS="-g -DDEBUG"

Now it seems that any search that is non-empty (i.e. matches
something) crashes with a duplicate In-Reply-To ID. This is in git
revision 92c4dcc (although it was the same yesterday).  The oddest
thing is that the second message-id is a common English word.

Here is a trace

dulcinea:~/tmp % ~/projects/notmuch/notmuch search spam
Query string is:
spam
Final query is:
Xapian::Query((Tmail AND Zspam:(pos=1)))
Query string is:
thread:13c033781712e92541a5591320ac0ff4
Query string is:
thread:13c033781712e92541a5591320ac0ff4 AND (spam)
Final query is:
Xapian::Query((Tmail AND 0 * G13c033781712e92541a5591320ac0ff4))
Final query is:
Xapian::Query((Tmail AND 0 * G13c033781712e92541a5591320ac0ff4 AND Zspam:(pos=1)))
Internal error: Message 877htzhn9e.wl%jemarch at gnu.org has duplicate In-Reply-To IDs: 1e5bcefd0911081424p12eb6fa9te57ff4cfeb83fcdd at mail.gmail.com and data
 (lib/message.cc:326).

At the moment I don't have any real good ideas for how to debug this
(or any real familiarity with notmuch internals).  I put a test corpus
of messages (all from public mailing lists) at

   http://pivot.cs.unb.ca/scratch/mailtest.tgz

The current tarball is about 5M.  The machine has plenty of bandwidth
(not meant as a challenge to DDOS hobbyists :) ).

d