Serial number zero and sequence space arithmetic

[LaMont Jones]

> That's not the situation I'm describing.  From BIND 4.8.1 on--
> possibly until a late BIND 8 release--a slave that detects that
> its master has a serial number of zone for a zone will *always*
> transfer that zone, regardless of what serial number the slave
> holds for that zone.

8.1.2-REL says:
	if (SEQ_GT(zp_start.z_serial, serial_no) || !serial_no) {

8.2.2-P5 says:
	if (SEQ_GT(zp_start.z_serial, serial_no) || !check_serial) {

	check_serial is not found in 8.1.2-REL, and is set when named
	parses the -s option.

So it looks like (based on other things in 8.2.2) that it may have
come in as part of the ixfr changes, which would tend to date it
back to 8.2, but I don't have those sources on line.

lamont