fix: only apply and log p3 and p6 when they are not zero

Pull-Request: #6097.

Author: diegomrsantos

protocols/gossipsub/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 - Remove `Rpc` from the public API.
   See [PR 6091](https://github.com/libp2p/rust-libp2p/pull/6091)
+- Fix applying P3 and P6 Score penalties when their weight is zero
+  See [PR 6097](https://github.com/libp2p/rust-libp2p/pull/6097)
 
 ## 0.49.0
 

protocols/gossipsub/src/peer_score.rs

@@ -311,11 +311,14 @@ impl PeerScore {
                 if topic_stats.mesh_message_deliveries_active
                     && topic_stats.mesh_message_deliveries
                         < topic_params.mesh_message_deliveries_threshold
+                    && topic_params.mesh_message_deliveries_weight != 0.0
                 {
                     let deficit = topic_params.mesh_message_deliveries_threshold
                         - topic_stats.mesh_message_deliveries;
                     let p3 = deficit * deficit;
-                    topic_score += p3 * topic_params.mesh_message_deliveries_weight;
+                    let penalty = p3 * topic_params.mesh_message_deliveries_weight;
+
+                    topic_score += penalty;
                     #[cfg(feature = "metrics")]
                     report
                         .penalties
@@ -324,7 +327,7 @@ impl PeerScore {
                         peer=%peer_id,
                         %topic,
                         %deficit,
-                        penalty=%topic_score,
+                        penalty=%penalty,
                         "[Penalty] The peer has a mesh deliveries deficit and will be penalized"
                     );
                 }
@@ -367,7 +370,9 @@ impl PeerScore {
             // addr. It is quadratic, and the weight is negative (validated by
             // peer_score_params.validate()).
             if let Some(peers_in_ip) = self.peer_ips.get(ip).map(|peers| peers.len()) {
-                if (peers_in_ip as f64) > self.params.ip_colocation_factor_threshold {
+                if (peers_in_ip as f64) > self.params.ip_colocation_factor_threshold
+                    && self.params.ip_colocation_factor_weight != 0.0
+                {
                     let surplus = (peers_in_ip as f64) - self.params.ip_colocation_factor_threshold;
                     let p6 = surplus * surplus;
                     #[cfg(feature = "metrics")]