From 96aafcebace8e0449477674ed5d2f03c80a5e4c9 Mon Sep 17 00:00:00 2001
From: gongzhiyong <gongzhiyong@gongzhiyongdeMacBook-Air.local>
Date: Wed, 15 Apr 2026 02:49:41 +0800
Subject: [PATCH] =?UTF-8?q?fix(P0):=20=E4=BF=AE=E5=A4=8D=E5=8F=91=E9=80=81?=
 =?UTF-8?q?=E6=B6=88=E6=81=AF=E5=90=8E=E4=B8=BB=E5=8C=BA=E5=9F=9F=E8=B7=B3?=
 =?UTF-8?q?=E5=9B=9E=E6=AC=A2=E8=BF=8E=E5=B1=8F?=
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---
 langgraph/src/main.tsx | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/langgraph/src/main.tsx b/langgraph/src/main.tsx
index 6f0c6ee..9e59f56 100644
--- a/langgraph/src/main.tsx
+++ b/langgraph/src/main.tsx
@@ -98,7 +98,7 @@ function App() {
   }, []);
 
   // Clear error and stale stream state when thread switches.
-  // Skip when doSubmit already called switchThread manually (to avoid clearing mid-stream).
+  // Skip when doSubmit set the flag (new thread created during submit — don't clear mid-stream).
   useEffect(() => {
     if (skipNextSwitchRef.current) {
       skipNextSwitchRef.current = false;
@@ -217,12 +217,11 @@ function App() {
       setConcurrentStatus("idle");
       return;
     }
-    // Only need to switchThread manually when a new thread was just created.
-    // For existing threads, currentThreadId didn't change so useEffect won't fire.
-    // Setting the skip flag prevents the useEffect from re-firing and clearing messages.
+    // For a newly created thread, currentThreadId just changed so the useEffect
+    // would call thread.switchThread() which clears thread.messages mid-stream.
+    // Skip it — useStream already uses the updated threadId prop from currentThreadId.
     if (!currentThreadId) {
       skipNextSwitchRef.current = true;
-      thread.switchThread(activeThreadId);
     }
 
     try { localStorage.removeItem(`draft_${activeThreadId}`); } catch { /* ignore */ }