New IPv6 clients are not resolved until another new client is added

[ranger81]

Hi,

I upgraded my Pi-Hole installation from 5.25.2 to the 6.0.2 release and I noticed a new behavior in how new IPv6 clients are resolved to their hostnames with PTR queries.

I saw below change in the code base between 5.x and 6.x. It adds a delay in resolving new IPv6 clients.

FTL/src/resolve.c

Lines 946 to 958 in ac500d5

	// If onlynew flag is set, we will only resolve new clients.
	// However, if this is a IPv6 client, we postpone the resolution
	// slightly to ensure the network table has had time to possibly
	// correlate the IPv6 address via a related other address (e.g.,
	// IPv4 address) though an identical MAC address.
	if(onlynew && newflag && IPv6 && client->firstSeen + DELAY_V6_RESOLUTION > now)
	{
	log_debug(DEBUG_RESOLVER, "Postponing resolution of new client %s (IPv6) for at least %.0f more seconds",
	getstr(ippos), now - client->firstSeen + DELAY_V6_RESOLUTION);
	skipped++;
	continue;
	}

The caveat is, that, as long as resolver.refreshNames is not set to ALL, that client hostname is never going to be resolved, except, if there is another new client (after the delay time). In that case, the previous client hostname is resolved.

Is this the expected behavior? I would have expected, that at least after the delay, that new IPv6 client should be resolved even though resolver.refreshNames is set to the default value of IPV4_ONLY. What is the wanted behavior here?