From ce274265db8af73e28624ecc1fc98cc984658844 Mon Sep 17 00:00:00 2001
From: mxsm <ljbmxsm@gmail.com>
Date: Mon, 8 Aug 2022 17:11:14 +0800
Subject: [PATCH] [ISSUE #4794] Fix deserialize ElectMasterResponseHeader
 attribute value of brokerMemberGroup is null (#4796)

---
 .../rocketmq/common/protocol/body/BrokerMemberGroup.java    | 3 ++-
 .../controller/impl/manager/ReplicasInfoManager.java        | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/common/src/main/java/org/apache/rocketmq/common/protocol/body/BrokerMemberGroup.java b/common/src/main/java/org/apache/rocketmq/common/protocol/body/BrokerMemberGroup.java
index eb02f88678..7e24da3640 100644
--- a/common/src/main/java/org/apache/rocketmq/common/protocol/body/BrokerMemberGroup.java
+++ b/common/src/main/java/org/apache/rocketmq/common/protocol/body/BrokerMemberGroup.java
@@ -21,8 +21,9 @@ import com.google.common.base.Objects;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import org.apache.rocketmq.remoting.protocol.RemotingSerializable;
 
-public class BrokerMemberGroup {
+public class BrokerMemberGroup extends RemotingSerializable {
     private String cluster;
     private String brokerName;
     private Map<Long/* brokerId */, String/* broker address */> brokerAddrs;
diff --git a/controller/src/main/java/org/apache/rocketmq/controller/impl/manager/ReplicasInfoManager.java b/controller/src/main/java/org/apache/rocketmq/controller/impl/manager/ReplicasInfoManager.java
index be53e2d876..a53c7ca9d7 100644
--- a/controller/src/main/java/org/apache/rocketmq/controller/impl/manager/ReplicasInfoManager.java
+++ b/controller/src/main/java/org/apache/rocketmq/controller/impl/manager/ReplicasInfoManager.java
@@ -211,8 +211,10 @@ public class ReplicasInfoManager {
                 response.setNewMasterAddress(candidate);
                 response.setMasterEpoch(masterEpoch + 1);
                 response.setSyncStateSetEpoch(syncStateSetEpoch);
-                response.setBrokerMemberGroup(buildBrokerMemberGroup(brokerName));
-
+                BrokerMemberGroup brokerMemberGroup = buildBrokerMemberGroup(brokerName);
+                if (null != brokerMemberGroup) {
+                    result.setBody(brokerMemberGroup.encode());
+                }
                 final ElectMasterEvent event = new ElectMasterEvent(brokerName, candidate);
                 result.addEvent(event);
                 return true;