Serial number zero and sequence space arithmetic

[Cricket Liu]

> > 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.

I'd bet it was 8.2, too.  That's when the semantics of using
multiple masters changed and the surrounding code was fairly
extensively modified.

cricket