1 files changed, 12 insertions, 5 deletions
diff --git a/src/document/sync.rs b/src/document/sync.rs
index bfa0fef..688d455 100644
--- a/src/document/sync.rs
+++ b/src/document/sync.rs
@@ -564,11 +564,18 @@ impl SyncSession {
         doc: &Document,
         before: &[crate::document::ChangeHash],
     ) -> usize {
-        let changes = doc.get_changes_meta(before);
-        for change in &changes {
-            self.state.sent_hashes.insert(change.hash);
-        }
-        changes.len()
+        let hashes: Vec<_> = doc
+            .get_changes_meta(before)
+            .iter()
+            .map(|c| c.hash)
+            .collect();
+        self.these_came_from_peer(&hashes)
+    }
+
+    /// `came_from_peer`, for the changes `hashes` (found already).
+    pub(crate) fn these_came_from_peer(&mut self, hashes: &[crate::document::ChangeHash]) -> usize {
+        self.state.sent_hashes.extend(hashes.iter().copied());
+        hashes.len()
     }
 
     /// Of the changes in `doc` beyond `from`, how many the peer has too, as far as we