BUG: "localhost" dns always returns both ipv4 and ipv6 regardless of queryStrategy!

[patterniha]

After I changed my internet isp the bug in example 1 in #4268 no longer occurred.
probably my isp didn't allow to use non-default udp dns and i thought the problem was with v2rayng.

but bug in example 2 still remains.
so i closed #4268 and open this separate issue for only example 2.

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

test version: 1.9.32
built-in dns server for "localhost" dns doesn't work correctly.
according to https://xtls.github.io/config/dns.html#dnsobject
after xray-core v1.8.6 built-in dns server support "global" and "per server" queryStrategy.
so according to the documentation,
for example if "global queryStrategy" is UseIP and "dns server 1 queryStrategy" is UseIPv4,
dns server 1 should only return ipv4 and final result should only contain ipv4(if for example
we have only server 1 dns server)
but if we start vpn for this config
and run for example "host cloudflare.com" command in termux(terminal)
result contains both ipv4 and ipv6!!!

*** instead of "localhost" if we use other types of dns (udp,tcp,doh,...) it works correctly. (dns query result contains only ipv4)

example config with "localhost" dns which incorrectly returns both IPv4 and ipv6: https://raw.githubusercontent.com/patterniha/xray_configs/refs/heads/main/2dust_with_bug_example_2.json

example config with "udp" dns which correctly only returns ipv4: https://raw.githubusercontent.com/patterniha/xray_configs/refs/heads/main/2dust_bug-free_example_2.json

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

localhost(system default) dns are very widely used in Iran.
because for fragment-used configs we should use domestic dns.
and because many isp don't allow to use non-default dns, we have to use "localhost" dns.

[patterniha]

@2dust
after testing in my pc, I realized this bug is related to the xray-core.