From b27dc26be3e93c4668c940cfa5154be47fc5efba Mon Sep 17 00:00:00 2001
From: Hwwwww-dev <47653238+Hwwwww-dev@users.noreply.github.com>
Date: Mon, 19 Jan 2026 16:06:36 +0800
Subject: [PATCH] fix: Update answer concatenation logic to handle overlapping
 values (#12676)

### What problem does this PR solve?

Update answer concatenation logic to handle overlapping values

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
---
 web/src/hooks/logic-hooks.ts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/web/src/hooks/logic-hooks.ts b/web/src/hooks/logic-hooks.ts
index 1f7909016..25b2589ff 100644
--- a/web/src/hooks/logic-hooks.ts
+++ b/web/src/hooks/logic-hooks.ts
@@ -274,8 +274,17 @@ export const useSendMessageWithSse = (
                 const val = JSON.parse(value?.data || '');
                 const d = val?.data;
                 if (typeof d !== 'boolean') {
+
                   setAnswer((prev) => {
-                    let newAnswer = (prev.answer || '') + (d.answer || '');
+                    const prevAnswer = prev.answer || '';
+                    const currentAnswer = d.answer || '';
+
+                    let newAnswer: string;
+                    if (prevAnswer && currentAnswer.startsWith(prevAnswer)) {
+                      newAnswer = currentAnswer;
+                    } else {
+                      newAnswer = prevAnswer + currentAnswer;
+                    }
 
                     if (d.start_to_think === true) {
                       newAnswer = newAnswer + '<think>';