"max-journal-size" is set by default to twice the size of the zone
database. however, the calculation of zone database size was flawed.
- change the size calculations in dns_db_getsize() to more accurately
represent the space needed for a journal file or *XFR message to
contain the data in the database. previously we returned the sizes
of all rdataslabs, including header overhead and offset tables,
which resulted in the database size being reported as much larger
than the equivalent journal transactions would have been.
- map files caused a particular problem here: the full name can't be
determined from the node while a file is being deserialized, because
the uppernode pointers aren't set yet. so we store "full name length"
in the dns_rbtnode structure while serializing, and clear it after
deserialization is complete.
c5405c2700