plugin/file: fix panic in miekg/dns.CompareDomainName()
@@ -372,7 +372,7 @@ func (z *Zone) additionalProcessing(answer []dns.RR, do bool) (extra []dns.RR) {
case *dns.MX:
name = x.Mx
}
- if !dns.IsSubDomain(z.origin, name) {
+ if len(name) == 0 || !dns.IsSubDomain(z.origin, name) {
continue
}
