Mailbox corruption (dovecot 2.2.13, Debian 8)

Hello.

The attached mbox folder becomes corrupted in the server when being retrieved by fetchmail using the --folder option.

This happens on a system running Debian jessie (i.e. dovecot 2.2.13) using the default configuration.

I've reported this to Debian here:

https://bugs.debian.org/776094

but I thought it would be good to post it here as well in case it is still a bug in the latest version (well, if it's not anymore a bug in the latest version, a patch against 2.2.13 will surely help the Debian maintainer in either case).

Thanks.