3 files changed, 26 insertions, 0 deletions
diff --git a/crates/tor-proto/src/channel/circmap.rs b/crates/tor-proto/src/channel/circmap.rs
index 496b8aee0..1e585bf51 100644
--- a/crates/tor-proto/src/channel/circmap.rs
+++ b/crates/tor-proto/src/channel/circmap.rs
@@ -269,6 +269,24 @@ impl CircMap {
         })
     }
 
+    /// Returns `true` if the circuit with the specified `id`
+    /// is open or opening.
+    ///
+    /// Returns `false` if the circuit is not in the circuit map,
+    /// or if we have already sent a DESTROY on it.
+    pub(super) fn is_open(&self, id: CircId) -> bool {
+        let Some(entry) = self.m.get(&id) else {
+            return false;
+        };
+
+        match entry {
+            CircEnt::Opening { .. } | CircEnt::OpenOrigin { .. } => true,
+            #[cfg(feature = "relay")]
+            CircEnt::OpenRelay { .. } => true,
+            CircEnt::DestroySent(..) => false,
+        }
+    }
+
     /// Inform the relevant circuit's padding subsystem that a given cell has been flushed.
     pub(super) fn note_cell_flushed(&mut self, id: CircId, info: QueuedCellPaddingInfo) {
         let padding_ctrl = match self.m.get(&id) {
diff --git a/crates/tor-proto/src/channel/reactor.rs b/crates/tor-proto/src/channel/reactor.rs
index 2e8dd2837..98e1859aa 100644
--- a/crates/tor-proto/src/channel/reactor.rs
+++ b/crates/tor-proto/src/channel/reactor.rs
@@ -846,7 +846,14 @@ impl<R: Runtime> Reactor<R> {
 
     /// Called when a circuit goes away: sends a DESTROY cell and removes
     /// the circuit.
+    ///
+    /// No-op if the circuit has already gone away,
+    /// (for example if we have already received DESTROY).
     async fn outbound_destroy_circ(&mut self, id: CircId) -> Result<()> {
+        if !self.circs.is_open(id) {
+            return Ok(());
+        }
+
         trace!(channel_id = %self, "Circuit {} is gone; sending DESTROY", id);
         // Remove the circuit's entry from the map: nothing more
         // can be done with it.
diff --git a/crates/tor-proto/src/channel/test_utils.rs b/crates/tor-proto/src/channel/test_utils.rs
index 9e2db0d9b..b107a53c8 100644
--- a/crates/tor-proto/src/channel/test_utils.rs
+++ b/crates/tor-proto/src/channel/test_utils.rs
@@ -314,6 +314,7 @@ impl ConnInspector {
     }
 
     /// Wait for the next message sent by the relay.
+    #[expect(dead_code)]
     pub(crate) async fn relay_cell(&mut self) -> Option<AnyChanCell> {
         self.relay_inspector_rx.recv().await.ok()
     }