#6580 defect assigned
twisted.names.server.DNSServerFactory should query child zones before parent zones
|Reported by:||Richard Wall||Owned by:||Richard Wall|
branch-diff, diff-cov, branch-cov, buildbot
twisted.names.server.DNSServerFactory (via ResolverChain), queries authorities in the order they appear in the supplied list.
If a parent zone (FileAuthority) precedes its child zones in the list, it may answer queries with NXDOMAIN or referral for names which should actually be answered by a child zone that contains the authoritative records.
DNSServerFactory should reorder its list of authorities so that child zones appear before their parent zones.
The order should be determined by the labels of the SOA names for each FileAuthority / SecondaryAuthority. This applies to the whole sequence of BindAuthority, PySourceAuthority and SecondaryAuthorityService that get loaded in t.n.tap.py. and passed t.n.server.DNSServerFactory.