If mail_index_move_to_memory() fails, make sure the future calls to it also will fail.
If mail_index_move_to_memory() fails, make sure the future calls to it also
will fail.

--HG--
branch : HEAD

dscho/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,dscho/dovecot,jwm/dovecot-notmuch,dscho/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,jwm/dovecot-notmuch,dscho/dovecot,dscho/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch