1 files changed, 33 insertions, 6 deletions

diff --git a/src/state/peer.rs b/src/state/peer.rs
index b723ccd..9f2da0f 100644
--- a/src/state/peer.rs
+++ b/src/state/peer.rs
@@ -39,6 +39,11 @@ impl Standing {
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub(crate) enum Liveness {
+    /// Nothing heard from it since this node started: known only from the member list
+    /// or another peer. It counts as active (sync, keepalives and dormancy treat it so)
+    /// until its first message makes it active, or `Timing::dormant_after` of silence
+    /// dormant.
+    Unknown,
     Active,
     /// No inbound message for Timing::dormant_after. Kept indefinitely, probed slowly.
     Dormant {
@@ -46,6 +51,12 @@ pub(crate) enum Liveness {
     },
 }
 
+impl Liveness {
+    pub(crate) fn is_dormant(self) -> bool {
+        matches!(self, Self::Dormant { .. })
+    }
+}
+
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub(crate) enum HelloState {
     #[default]
@@ -184,7 +195,7 @@ impl PeerState {
             hello_backoff: Backoff::new(HELLO_RETRY, HELLO_RETRY_MAX),
             probe_backoff: timing.probe_backoff(),
             sync: SyncSession::new(timing.sync_reply_backoff()),
-            liveness: Liveness::Active,
+            liveness: Liveness::Unknown,
             added_at: Instant::now(),
             last_seen: None,
             last_keepalive_at: None,
@@ -219,7 +230,7 @@ impl PeerState {
     /// An overdue sync answer from an established, active peer (see
     /// `SyncSession::take_overdue_reply`).
     pub(crate) fn take_overdue_sync_reply(&mut self, now: Instant) -> Option<usize> {
-        if self.liveness != Liveness::Active || self.hello_state != HelloState::Established {
+        if self.liveness.is_dormant() || self.hello_state != HelloState::Established {
             return None;
         }
         let overdue = self.sync.take_overdue_reply(now);
@@ -240,6 +251,9 @@ impl PeerState {
         self.unreachable_since = None;
         self.probe_backoff.reset();
 
+        if self.liveness == Liveness::Unknown {
+            self.liveness = Liveness::Active;
+        }
         if let Liveness::Dormant { since } = self.liveness {
             self.incidents.dormant_ms += now.saturating_duration_since(since).as_millis() as u64;
             self.liveness = Liveness::Active;
@@ -287,7 +301,7 @@ impl PeerState {
 
     /// Moves a silent peer to Dormant. Returns true on the transition.
     pub(crate) fn check_dormancy(&mut self, timing: &Timing, now: Instant) -> bool {
-        if self.liveness != Liveness::Active || self.quiet_for(now) < timing.dormant_after {
+        if self.liveness.is_dormant() || self.quiet_for(now) < timing.dormant_after {
             return false;
         }
 
@@ -340,7 +354,7 @@ impl PeerState {
         } else {
             timing.keepalive + timing.keepalive / 2
         };
-        let due = self.liveness == Liveness::Active
+        let due = !self.liveness.is_dormant()
             && self.hello_state == HelloState::Established
             && now.saturating_duration_since(self.added_at) >= timing.keepalive
             && self.quiet_for(now) >= quiet_enough
@@ -387,7 +401,7 @@ impl PeerState {
 
         // While an answer to our last sync message is due, a lost message is the reply
         // timeout's to resend; healing is for when neither side has anything outstanding.
-        if self.liveness != Liveness::Active
+        if self.liveness.is_dormant()
             || self.hello_state != HelloState::Established
             || self.sync.reply.is_some()
         {
@@ -413,7 +427,7 @@ impl PeerState {
     /// Heard from recently. A returning node counts as alive from its first message,
     /// before the handshake finishes, so a swarm-wide forget can't make it flap.
     pub(crate) fn is_alive(&self, timing: &Timing, now: Instant) -> bool {
-        self.liveness == Liveness::Active
+        !self.liveness.is_dormant()
             && self
                 .last_seen
                 .is_some_and(|t| now.saturating_duration_since(t) < timing.dormant_after)
@@ -424,6 +438,19 @@ impl PeerState {
 mod tests {
     use super::*;
 
+    /// Unknown until heard from; silent long enough, dormant like an active peer.
+    #[test]
+    fn unknown_until_heard_from() {
+        let timing = Timing::from_keepalive(Duration::from_secs(60), Duration::from_secs(300));
+        let mut heard = PeerState::new(true, &timing);
+        assert_eq!(heard.liveness, Liveness::Unknown);
+        assert!(!heard.mark_seen(heard.added_at), "no re-handshake: none yet");
+        assert_eq!(heard.liveness, Liveness::Active);
+        let mut silent = PeerState::new(true, &timing);
+        assert!(silent.check_dormancy(&timing, silent.added_at + timing.dormant_after));
+        assert!(silent.liveness.is_dormant());
+    }
+
     /// The two sides of a pair take turns: each sends every other interval.
     #[test]
     fn keepalives_take_turns() {