I started trying to generalize the regexp stuff to include message-ids [1], but didn't get that far. I think both of these patches are defensible on their own, particularly the second. I'll probably include something like them in a revised series for regexp searching. Probably we should use more of the the "release()" style memory management with Xapian; I didn't follow that up yet as I didn't want to get _too_ distracted from current goal. [1]: the complication is that message-ids are boolean fields, while from and subject are probabilistic. It's not insurmountable, but it did inspire re-thinking the way query fields are initialized.