maxage causes loss of local email

[Nicolas Sebrecht]

On Sun, Mar 22, 2015 at 11:27:33AM -0400, Janna Martl wrote:

> These edge cases are amplified if someone has a pre-existing
> Maildir and wants to start using offlineimap to sync it to a new
> remote. Maildir.py's _scanfolder() uses os.listdir(), which gives a
> list of filenames [F_1,...,F_n] with times [T_1,...,T_n] which are not
> in any kind of order. As with the examples we've been discussing,
> these are copied to the server and given UID's U_1, ..., U_n, where
> now U_i < U_{i+1}. Restrict the local messagelist based on maxage, and
> you get a seemingly random subset of U_i's. The cutoff point is the
> min of these, and if Fix #1 is applied, tons of messages with UID's >
> this but times earlier than this will be synced, causing the user to
> think something is wrong. I suppose this should be documented
> somewhere...

Plain right.

offlineimap.conf should tell there are known edge-cases with maxage and
point to the manual. The limitations ― conditions to hit the offending
cases ― are described in the "known issues" section of the manual
(docs/offlineimap.txt).

A detailed technical input about the processing logic (what the code
does) should be written for the website either in a dedicated page or in
the "Coding Guidelines" page. This is not critical but good to document.

Finally, it would be very nice to write a blog post together about the
situation before, the fix and all the faulty cases we explored and
talked about. IOW, how we came to this logic.

> OK, I'll do this tonight or tomorrow.

Fine!

-- 
Nicolas Sebrecht