fix: 添加messages为空校验

api/handler/chatimpl/chat_handler.go

@@ -252,6 +252,7 @@ func (h *ChatHandler) sendMessage(ctx context.Context, session *types.ChatSessio
 
 			// loading the role context
 			var messages []types.Message
+			if len(messages) > 0 {
 				err := utils.JsonDecode(role.Context, &messages)
 				if err == nil {
 					for _, v := range messages {
@@ -263,6 +264,7 @@ func (h *ChatHandler) sendMessage(ctx context.Context, session *types.ChatSessio
 						chatCtx = append(chatCtx, v)
 					}
 				}
+			}
 
 			// loading recent chat history as chat context
 			if chatConfig.ContextDeep > 0 {