From a7b85146fef5336ca61a08301d8733744d32268b Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Mon, 6 Apr 2020 23:10:28 +0200
Subject: [PATCH] Forgot to recalculate hash at strategic locations

---
 src/membership.rs | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/membership.rs b/src/membership.rs
index 8b067686..e468c9b0 100644
--- a/src/membership.rs
+++ b/src/membership.rs
@@ -70,9 +70,12 @@ impl Members {
 		nodes.sort_by_key(|(id, _status)| *id);
 
 		let mut hasher = Sha256::new();
+		eprintln!("Current set of pingable nodes: --");
 		for (id, status) in nodes {
+			eprintln!("{} {}", hex::encode(id), status.addr);
 			hasher.input(format!("{} {}\n", hex::encode(id), status.addr));
 		}
+		eprintln!("END --");
 		self.status_hash.copy_from_slice(&hasher.result()[..]);
 	}
 }
@@ -85,18 +88,20 @@ pub struct NodeStatus {
 
 impl System {
 	pub fn new(config: Config, id: UUID) -> Self {
-		System{
-			config,
-			id,
-			rpc_client: Client::new(),
-			members: RwLock::new(Members{
+		let mut members = Members{
 				status: HashMap::new(),
 				status_hash: [0u8; 32],
 				config: NetworkConfig{
 					members: HashMap::new(),
 					version: 0,
 				},
-			}),
+			};
+		members.recalculate_status_hash();
+		System{
+			config,
+			id,
+			rpc_client: Client::new(),
+			members: RwLock::new(members),
 		}
 	}
 
@@ -197,9 +202,9 @@ impl System {
 				propagate.push(node.clone());
 			}
 		}
-		drop(members);
 		
 		if propagate.len() > 0 {
+			members.recalculate_status_hash();
 			tokio::spawn(self.clone().broadcast(Message::AdvertiseNodesUp(propagate), PING_TIMEOUT));
 		}
 
@@ -242,9 +247,14 @@ impl System {
 					})).await;
 
 			let mut members = self.members.write().await;
+			let mut has_changes = false;
+
 			for (id, addr, ping_resp) in ping_resps {
 				if let Ok(Message::Ping(ping)) = ping_resp {
 					let is_new = members.handle_ping(addr.ip(), &ping);
+					if is_new {
+						has_changes = true;
+					}
 					if is_new || members.status_hash != ping.status_hash {
 						tokio::spawn(self.clone().pull_status(ping.id.clone()));
 					}
@@ -256,6 +266,7 @@ impl System {
 					if remaining_attempts == 0 {
 						eprintln!("Removing node {} after too many failed pings", hex::encode(id));
 						members.status.remove(id);
+						has_changes = true;
 					} else {
 						if let Some(st) = members.status.get_mut(id) {
 							st.remaining_ping_attempts = remaining_attempts - 1;
@@ -263,6 +274,9 @@ impl System {
 					}
 				}
 			}
+			if has_changes {
+				members.recalculate_status_hash();
+			}
 			drop(members);
 
 			restart_at.await