fix: #1612 fill empty message with a placeholder

app/components/chat.tsx

@@ -487,18 +487,26 @@ export function Chat() {
 
   // stop response
   const onUserStop = (messageId: number) => {
+    ChatControllerPool.stop(sessionIndex, messageId);
+  };
+
+  useEffect(() => {
     chatStore.updateCurrentSession((session) => {
       const stopTiming = Date.now() - REQUEST_TIMEOUT_MS;
       session.messages.forEach((m) => {
         // check if should stop all stale messages
-        if (m.streaming && new Date(m.date).getTime() < stopTiming) {
-          m.isError = false;
-          m.streaming = false;
+        if (new Date(m.date).getTime() < stopTiming) {
+          if (m.streaming) {
+            m.streaming = false;
+          }
+
+          if (m.content.length === 0) {
+            m.content = "No content in this message.";
+          }
         }
       });
     });
-    ChatControllerPool.stop(sessionIndex, messageId);
-  };
+  }, []);
 
   // check if should send message
   const onInputKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {