From c5040bd0a43f5835b3bb93d33ce26139c1dd0e51 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukas@zed.dev>
Date: Wed, 20 Aug 2025 15:41:58 +0200
Subject: [PATCH] remote: Do not leave client hanging on unhandled proto
 message (#36590)

Otherwise the client will wait for a response that never arrives,
causing the task to lock up

Release Notes:

- N/A
---
 crates/remote/src/ssh_session.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/crates/remote/src/ssh_session.rs b/crates/remote/src/ssh_session.rs
index 1c4409aec3..a26f4be661 100644
--- a/crates/remote/src/ssh_session.rs
+++ b/crates/remote/src/ssh_session.rs
@@ -2353,6 +2353,7 @@ impl ChannelClient {
                     build_typed_envelope(peer_id, Instant::now(), incoming)
                 {
                     let type_name = envelope.payload_type_name();
+                    let message_id = envelope.message_id();
                     if let Some(future) = ProtoMessageHandlerSet::handle_message(
                         &this.message_handlers,
                         envelope,
@@ -2391,6 +2392,15 @@ impl ChannelClient {
                             .detach()
                     } else {
                         log::error!("{}:unhandled ssh message name:{type_name}", this.name);
+                        if let Err(e) = AnyProtoClient::from(this.clone()).send_response(
+                            message_id,
+                            anyhow::anyhow!("no handler registered for {type_name}").to_proto(),
+                        ) {
+                            log::error!(
+                                "{}:error sending error response for {type_name}:{e:#}",
+                                this.name
+                            );
+                        }
                     }
                 }
             }