Re: bug: chokes on long directory names (was: Re: out of memory on idle machine)

[David Bremner <david@tethera.net>]

Gregor Zattler <telegraph@gmx.net> writes:

> Hi David, Olly, notmuch and xapian developers,
> * David Bremner <david@tethera.net> [11. Feb. 2021]:
>> David Bremner <david@tethera.net> writes:
>> As a kind of desperation move, you could try bisecting your mailstore,
>> to see how small of a set of messages you can duplicate the problem
>> with.
>
> this I did, somehow.  I found the culprit: It's a maildir
> with one single mail in it.  The name of the maildir is
> exceptionally long [because generated from a List-Id:
> -Header] and the mail arrived at the very day, my notmuch
> database corrupted.  This maildir alone provokes that every
> next notmuch new will rescan all (?) files.

Hi Gregor;

I am very impressed with your persistence. I suspect it is a bug in
notmuch. I don't know all the details yet, but in the normal case the
directory name is added to the database prefixed with XDIRECTORY. I
noticed this isn't happening in the case of directories 234 or
longer. That is roughly the Xapian term limit of 245 characters in
total. I'm not sure why the discrepency of one character, but the main
point is that notmuch is probably improperly ignoring an error from
Xapian when adding these overlong terms.

Thanks again for the debugging, I suspect would have never found this
bug on my own.

David