From 3166a5ba824ccb5ae849e0cbec6ecc84f9e67871 Mon Sep 17 00:00:00 2001
From: jif-oai <jif@openai.com>
Date: Tue, 3 Mar 2026 09:19:37 +0000
Subject: [PATCH] fix: agent race (#13248)

https://github.com/openai/codex/issues/13244
---
 codex-rs/core/src/agent/control.rs | 62 ++++++++++++++++++++++++------
 1 file changed, 51 insertions(+), 11 deletions(-)

diff --git a/codex-rs/core/src/agent/control.rs b/codex-rs/core/src/agent/control.rs
index 6327e1e3e..85f28b4f6 100644
--- a/codex-rs/core/src/agent/control.rs
+++ b/codex-rs/core/src/agent/control.rs
@@ -405,18 +405,20 @@ impl AgentControl {
         };
         let control = self.clone();
         tokio::spawn(async move {
-            let mut status_rx = match control.subscribe_status(child_thread_id).await {
-                Ok(rx) => rx,
-                Err(_) => return,
-            };
-            let mut status = status_rx.borrow().clone();
-            while !is_final(&status) {
-                if status_rx.changed().await.is_err() {
-                    status = control.get_status(child_thread_id).await;
-                    break;
+            let status = match control.subscribe_status(child_thread_id).await {
+                Ok(mut status_rx) => {
+                    let mut status = status_rx.borrow().clone();
+                    while !is_final(&status) {
+                        if status_rx.changed().await.is_err() {
+                            status = control.get_status(child_thread_id).await;
+                            break;
+                        }
+                        status = status_rx.borrow().clone();
+                    }
+                    status
                 }
-                status = status_rx.borrow().clone();
-            }
+                Err(_) => control.get_status(child_thread_id).await,
+            };
             if !is_final(&status) {
                 return;
             }
@@ -1296,6 +1298,44 @@ mod tests {
         assert_eq!(wait_for_subagent_notification(&parent_thread).await, true);
     }
 
+    #[tokio::test]
+    async fn completion_watcher_notifies_parent_when_child_is_missing() {
+        let harness = AgentControlHarness::new().await;
+        let (parent_thread_id, parent_thread) = harness.start_thread().await;
+        let child_thread_id = ThreadId::new();
+
+        harness.control.maybe_start_completion_watcher(
+            child_thread_id,
+            Some(SessionSource::SubAgent(SubAgentSource::ThreadSpawn {
+                parent_thread_id,
+                depth: 1,
+                agent_nickname: None,
+                agent_role: Some("explorer".to_string()),
+            })),
+        );
+
+        assert_eq!(wait_for_subagent_notification(&parent_thread).await, true);
+
+        let history_items = parent_thread
+            .codex
+            .session
+            .clone_history()
+            .await
+            .raw_items()
+            .to_vec();
+        assert_eq!(
+            history_contains_text(
+                &history_items,
+                &format!("\"agent_id\":\"{child_thread_id}\"")
+            ),
+            true
+        );
+        assert_eq!(
+            history_contains_text(&history_items, "\"status\":\"not_found\""),
+            true
+        );
+    }
+
     #[tokio::test]
     async fn spawn_thread_subagent_gets_random_nickname_in_session_source() {
         let harness = AgentControlHarness::new().await;