The .mmdb files and GeoIP2-Country-Test.json are MaxMind's published test
data from github.com/maxmind/MaxMind-DB, dual licensed MIT or Apache-2.0
(LICENSE-MIT, LICENSE-APACHE beside this file). All were fetched at commit
276926d23b4109ca5452709bfb5931c338afb34c. They contain test records only, not real geolocation data.
`pathological-dag.mmdb` is not MaxMind's: a 32-node IPv4 tree whose two
children are both the next node (2^32 network paths), built for the geoip
code review R8-1 regression. It must be refused by `OpenMMDBVerified`.
`pathological-empty-dag.mmdb` is a 128-node IPv6 tree whose children share
the next node and end in the empty sentinel: maxminddb's walk spends 2^128
steps inside one call. `pathological-metadata.mmdb` declares node_count
2^63, which overflows the library's own arithmetic and panics it. Both are
for the geoip code review R9 regressions: only the console's verifier
child may ever open them.
`pathological-bigmap.mmdb` has one data record declaring a map of
16,843,036 entries: maxminddb allocates it before noticing the entries are
missing. The verifier child's memory cap must contain it.