Xapian discuss - Mar 2018 - bug: "no top level messages" crash on Zen email loops

Antoine Beaupré <anarcat at orangeseeds.org> writes:
> On 2018-03-19 13:36:49, David Bremner wrote:
>>
>> I can't duplicate that part.  
>
> That's very strange. I can reproduce this on my workstation here, but
> taking the tarball I sent in the original message, I can't reproduce
> anymore. So something changed! I suspect it's the "flags" on
the
> message. I have "F" everywhere because I'm experimenting with
syncing
> (badly) my inbox tag everywhere, through the flagged tag. All post-new
> hooks stuff that shouldn't affect this because it's in a new
> environment, but it does change the flag on the files sometimes.
>
> So attached is a *new* reproducer, with which I *can* reproduce in a
> clean VM with notmuch from stretch (0.23?).
I can confirm this reproduces both the xapian-check and the notmuch-show
error. Olly agrees that whatever notmuch is doing wrong, it shouldn't
lead to a corrupted database (unless we reach around the API and access
files directly, which I don't think we do).

d

On Mon, Mar 19, 2018 at 05:03:21PM -0300, David Bremner
wrote:
> I can confirm this reproduces both the xapian-check and the notmuch-show
> error. Olly agrees that whatever notmuch is doing wrong, it shouldn't
> lead to a corrupted database
There was a Xapian bug here, which I fixed on master last week and will
be fixed in 1.4.6.

If changes to a new database which didn't modify the termlist table were
committed, then a disk block which had been allocated to be the root
block in the termlist table was leaked (not used but not on the
freelist of blocks the table can recycle).  This was largely harmless,
except that it was detected by Database::check() and caused an error.

Cheers,
    Olly

On 2018-03-29 04:17:21, Olly Betts wrote:
> On Mon, Mar 19, 2018 at 05:03:21PM -0300, David Bremner wrote:
>> I can confirm this reproduces both the xapian-check and the
notmuch-show
>> error. Olly agrees that whatever notmuch is doing wrong, it
shouldn't
>> lead to a corrupted database
>
> There was a Xapian bug here, which I fixed on master last week and will
> be fixed in 1.4.6.
An honor. It's not every day you find a bug in a database software. ;)
> If changes to a new database which didn't modify the termlist table
were
> committed, then a disk block which had been allocated to be the root
> block in the termlist table was leaked (not used but not on the
> freelist of blocks the table can recycle).  This was largely harmless,
> except that it was detected by Database::check() and caused an error.
Hmm... but if I understand correctly, that's one part of the story: I
could get that error and not have the problem with `notmuch show`. Does
that *also* resolve the issue with email loops?

A.

-- 
Travail, du latin Tri Palium trois pieux, instrument de torture.