From 51777790660a8b678586e145465d7c824d00f7e9 Mon Sep 17 00:00:00 2001
From: imhao183 <wildfirechat86@gmail.com>
Date: Wed, 1 Jul 2020 14:20:04 +0800
Subject: [PATCH] fix server api group operation failure issue

---
 broker/src/main/java/io/moquette/imhandler/GroupHandler.java | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/broker/src/main/java/io/moquette/imhandler/GroupHandler.java b/broker/src/main/java/io/moquette/imhandler/GroupHandler.java
index ff0e02f8..62670b33 100644
--- a/broker/src/main/java/io/moquette/imhandler/GroupHandler.java
+++ b/broker/src/main/java/io/moquette/imhandler/GroupHandler.java
@@ -19,6 +19,8 @@ abstract public class GroupHandler<T> extends IMHandler<T> {
     protected void sendGroupNotification(String fromUser, String targetId, List<Integer> lines, WFCMessage.MessageContent content) {
         if (lines == null) {
             lines = new ArrayList<>();
+        } else {
+            lines = new ArrayList<>(lines);
         }
 
         if (lines.isEmpty()) {