protocols/relay: Don't duplicate p2p protocol in relay reservation (#2696) (#2701)

protocols/relay/CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - Update to `libp2p-swarm` `v0.37.0`.
 
+- Do not duplicate the p2p/xxx component with the relay PeerId when a client requests a reservation. See [PR 2701].
+
+[PR 2701]: https://github.com/libp2p/rust-libp2p/pull/2701/
+
 # 0.9.1
 
 - Respond to at most one incoming reservation request. Deny <= 8 incoming

protocols/relay/src/v2/relay.rs

@@ -756,9 +756,13 @@ impl Action {
                     inbound_reservation_req,
                     addrs: poll_parameters
                         .external_addresses()
-                        .map(|a| {
-                            a.addr
-                                .with(Protocol::P2p((*poll_parameters.local_peer_id()).into()))
+                        .map(|a| a.addr)
+                        // Add local peer ID in case it isn't present yet.
+                        .filter_map(|a| match a.iter().last()? {
+                            Protocol::P2p(_) => Some(a),
+                            _ => Some(
+                                a.with(Protocol::P2p(*poll_parameters.local_peer_id().as_ref())),
+                            ),
                         })
                         .collect(),
                 }),