MDEV-24509 : Warning: Memory not freed: 56 on SET @@global.wsrep_sst_auth

It seems that memory is not freed when updated value is NULL or
when wsrep is not initialized before shutdown.

mysql-test/suite/galera/r/galera_var_sst_auth.result

-#
-# MDEV-10492: Assertion failure on shutdown when wsrep_sst_auth set in config
-#
 SELECT @@global.wsrep_sst_auth;
 @@global.wsrep_sst_auth
 ********
@@ -8,5 +5,14 @@ SET @@global.wsrep_sst_auth='foo:bar';
 SELECT @@global.wsrep_sst_auth;
 @@global.wsrep_sst_auth
 ********
-disconnect node_2;
-disconnect node_1;
+connection node_2;
+SET @@global.wsrep_sst_auth= 'abcdefghijklmnopqrstuvwxyz';
+SELECT @@global.wsrep_sst_auth;
+@@global.wsrep_sst_auth
+********
+Shutdown node_2
+connection node_1;
+connection node_2;
+SELECT @@global.wsrep_sst_auth;
+@@global.wsrep_sst_auth
+********

mysql-test/suite/galera/t/galera_var_sst_auth.test

 --source include/galera_cluster.inc
 --source include/have_innodb.inc
 
---echo #
---echo # MDEV-10492: Assertion failure on shutdown when wsrep_sst_auth set in config
---echo #
+#
+# MDEV-10492: Assertion failure on shutdown when wsrep_sst_auth set in config
+#
 
 SELECT @@global.wsrep_sst_auth;
 SET @@global.wsrep_sst_auth='foo:bar';
 SELECT @@global.wsrep_sst_auth;
 
---source include/galera_end.inc
+#
+# MDEV-24509 Warning: Memory not freed: 56 on SET @@global.wsrep_sst_auth
+#
+--connection node_2
+SET @@global.wsrep_sst_auth= 'abcdefghijklmnopqrstuvwxyz';
+SELECT @@global.wsrep_sst_auth;
+--echo Shutdown node_2
+--source include/shutdown_mysqld.inc
+
+# On node_1, verify that the node has left the cluster.
+--connection node_1
+--let $wait_condition = SELECT VARIABLE_VALUE = 1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
+--source include/wait_condition.inc
+
+# Restart node_2
+--connection node_2
+--source include/start_mysqld.inc
+--let $wait_condition = SELECT VARIABLE_VALUE = 2 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_cluster_size';
+--source include/wait_condition.inc
+SELECT @@global.wsrep_sst_auth;
+
+

sql/mysqld.cc

@@ -2011,8 +2011,11 @@ static void __cdecl kill_server(int sig_ptr)
 
   close_connections();
 
+#ifdef WITH_WSREP
   if (wsrep_inited == 1)
     wsrep_deinit(true);
+  wsrep_sst_auth_free();
+#endif /* WITH_WSREP */
 
   if (sig != MYSQL_KILL_SIGNAL &&
       sig != 0)
@@ -2132,6 +2135,7 @@ extern "C" void unireg_abort(int exit_code)
     /* In bootstrap mode we deinitialize wsrep here. */
     if (opt_bootstrap && wsrep_inited)
       wsrep_deinit(true);
+    wsrep_sst_auth_free();
   }
 #endif // WITH_WSREP
 

sql/wsrep_sst.cc

@@ -149,6 +149,12 @@ static bool sst_auth_real_set (const char* value)
       if (wsrep_sst_auth) { my_free((void*) wsrep_sst_auth); }
       wsrep_sst_auth= my_strdup(WSREP_SST_AUTH_MASK, MYF(0));
     }
+    else
+    {
+      if (wsrep_sst_auth) { my_free((void*) wsrep_sst_auth); }
+      wsrep_sst_auth= NULL;
+    }
+
     return 0;
   }
   return 1;