From c48f7319ca05a26a4b06b5160d34cc78e8a4682f Mon Sep 17 00:00:00 2001
From: ZhenYi <434836402@qq.com>
Date: Thu, 30 Apr 2026 23:37:13 +0800
Subject: [PATCH] fix(chat): handle multi-byte character truncation in tool
 result preview

---
 libs/agent/chat/service.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libs/agent/chat/service.rs b/libs/agent/chat/service.rs
index 3316fa7..2ae3d6d 100644
--- a/libs/agent/chat/service.rs
+++ b/libs/agent/chat/service.rs
@@ -791,7 +791,13 @@ impl ChatService {
                             crate::tool::ToolResult::Error(msg) => msg.clone(),
                         };
                         let preview = if text.len() > 300 {
-                            format!("{}...", &text[..300])
+                            let end = text
+                                .char_indices()
+                                .map(|(i, _)| i)
+                                .take_while(|&i| i <= 300)
+                                .last()
+                                .unwrap_or(300);
+                            format!("{}...", &text[..end])
                         } else {
                             text.clone()
                         };