predecessors go along

1 files changed, 18 insertions, 3 deletions

diff --git a/src/swarm/tree.rs b/src/swarm/tree.rs
index 20df2ec..ffdf80e 100644
--- a/src/swarm/tree.rs
+++ b/src/swarm/tree.rs
@@ -361,7 +361,9 @@ pub(crate) async fn plan(state: &AppState, writer: u64) -> Option<Plan> {
 /// them (`SyncSession::known_to_peer`): else, with writers in turn, each change coming
 /// along another tree, the next message we pass on to one would carry all we got since
 /// our last to it, mostly what its other parents brought it. Should one lack them after
-/// all, it asks, and gets them (`resend_if_needed`).
+/// all, it asks, and gets them (`resend_if_needed`). But to our children, those of
+/// them that `changes` build on go along, if they were counted so lately
+/// (`SyncSession::with_predecessors`).
 pub(crate) async fn forward(
     state: &AppState,
     writer: u64,
@@ -372,15 +374,28 @@ pub(crate) async fn forward(
     if !changes.is_empty() {
         for neighbour in &plan.covered {
             if let Some(peer_state) = state.get_peer_state(neighbour).await {
-                peer_state.lock().await.sync.known_to_peer(changes);
+                peer_state
+                    .lock()
+                    .await
+                    .sync
+                    .known_to_peer(changes, tokio::time::Instant::now());
             }
         }
     }
     plan.children.retain(|child| child != from);
     let children = &plan.children;
+    let replica = if changes.is_empty() {
+        None
+    } else {
+        Some(state.doc.read().await)
+    };
     for child in children {
         if let Some(peer_state) = state.get_peer_state(child).await {
-            peer_state.lock().await.tree_writer = Some(writer);
+            let mut peer_state = peer_state.lock().await;
+            peer_state.tree_writer = Some(writer);
+            if let Some(replica) = &replica {
+                peer_state.sync.with_predecessors(&replica.doc, changes);
+            }
         }
         state.stats.tree_forward();
         state.request_sync(child);