fix: only add scope to unicast link local v6 addresses when printing

[hrzlgnm]

The scope id only makes sense in case the address is a v6 uni-cast link local address.

Before the change the output of the query example, facing multiple ipv6 addresses with different scopes would be:

At 7.939648ms: Resolved a new service: FritzBoxRepeater._fbox._tcp.local.
 host: FritzBoxRepeater.fritz.box.
 port: 49000
 Address: 192.168.178.89
 Address: fd00::ca0e:14ff:feff:416%enp12s0 <- is an ULA (Unique Local Address, fc00::/7)
 Address: 2003:e8:bf1e:9b00:ca0e:14ff:feff:416%enp12s0 <- is globally scoped
 Address: fe80::ca0e:14ff:feff:416%enp12s0 <- only here it makes sense

After:

At 6.967689ms: Resolved a new service: FritzBoxRepeater._fbox._tcp.local.
host: FritzBoxRepeater.fritz.box.
port: 49000
Address: 2003:e8:bf1e:9b00:ca0e:14ff:feff:416
Address: fd00::ca0e:14ff:feff:416
Address: 192.168.178.89
Address: fe80::ca0e:14ff:feff:416%enp12s0

[hrzlgnm]

Ah this won't work without updating rust to 1.84.0, perhaps something to be done when bumping the MSRV to 1.84

[keepsimple1]

Ah this won't work without updating rust to 1.84.0, perhaps something to be done when bumping the MSRV to 1.84

Can you use this helper we already have:

mdns-sd/src/service_info.rs

Lines 1232 to 1237 in 3f34136

	/// Returns true if `addr` is a unicast link-local IPv6 address.
	/// Replicates the logic from `std::net::Ipv6Addr::is_unicast_link_local()`, which is not
	/// stable on the current mdns-sd Rust version (1.71.0).
	///
	/// https://github.com/rust-lang/rust/blob/9fc6b43126469e3858e2fe86cafb4f0fd5068869/library/core/src/net/ip_addr.rs#L1684
	fn is_unicast_link_local(addr: &Ipv6Addr) -> bool {

[hrzlgnm]

Ah this won't work without updating rust to 1.84.0, perhaps something to be done when bumping the MSRV to 1.84

Can you use this helper we already have:

mdns-sd/src/service_info.rs

Lines 1232 to 1237 in 3f34136

	/// Returns true if `addr` is a unicast link-local IPv6 address.
	/// Replicates the logic from `std::net::Ipv6Addr::is_unicast_link_local()`, which is not
	/// stable on the current mdns-sd Rust version (1.71.0).
	///
	/// https://github.com/rust-lang/rust/blob/9fc6b43126469e3858e2fe86cafb4f0fd5068869/library/core/src/net/ip_addr.rs#L1684
	fn is_unicast_link_local(addr: &Ipv6Addr) -> bool {

Thanks for pointing it out, I totally forgot about that helper.

[keepsimple1]

LGTM!