Make sure cache is opened when mail_cache_field_can_add() or mail_cache_field_want_add() is called.
Make sure cache is opened when mail_cache_field_can_add() or
mail_cache_field_want_add() is called.

--HG--
branch : HEAD

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