From a8db7c4bef38d0842fa9489ea861fbc08db54075 Mon Sep 17 00:00:00 2001
From: yuqei <cyuqei@gmail.com>
Date: Mon, 22 Jun 2026 11:13:07 +0800
Subject: [PATCH] fix: stabilize legal chat streaming

---
 frontend/src/app/chat/page.tsx | 14 ++++++--------
 frontend/src/services/chat.ts  |  2 +-
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/frontend/src/app/chat/page.tsx b/frontend/src/app/chat/page.tsx
index b1a965d4..eddf7b23 100644
--- a/frontend/src/app/chat/page.tsx
+++ b/frontend/src/app/chat/page.tsx
@@ -655,18 +655,16 @@ function normalizeMessagesForDisplay(items: ChatMessage[], lastQuestion: string,
 }
 
 function mergeAssistantContent(previous: string, incoming: string) {
-  const trimmedPrevious = previous.trim();
-  const trimmedIncoming = incoming.trim();
-  if (!trimmedIncoming) {
+  if (!incoming) {
     return previous;
   }
-  if (!trimmedPrevious) {
-    return trimmedIncoming;
+  if (!previous) {
+    return incoming.trimStart();
   }
-  if (trimmedIncoming.startsWith(trimmedPrevious)) {
-    return trimmedIncoming;
+  if (incoming.startsWith(previous)) {
+    return incoming;
   }
-  return `${trimmedPrevious}\n\n${trimmedIncoming}`;
+  return `${previous}${incoming}`;
 }
 
 function dedupeMessages(items: ChatMessage[]): ChatMessage[] {
diff --git a/frontend/src/services/chat.ts b/frontend/src/services/chat.ts
index 114e3c5c..28c78d2f 100644
--- a/frontend/src/services/chat.ts
+++ b/frontend/src/services/chat.ts
@@ -8,7 +8,7 @@ import {
 } from "@/services/http";
 import type { ChatSourceItem, ChatStreamEvent, ConversationDetail, ConversationListItem, PageResponse, ReviewChatContext } from "@/types/api";
 
-const STREAM_TIMEOUT_MS = 30000;
+const STREAM_TIMEOUT_MS = 180000;
 
 export type StreamChatParams = {
   message: string;