MDEV-17852 Altered connection limits for user have no effect

update mqh in struct user_conn after taking it from the cache

mysql-test/r/user_limits.result

@@ -186,3 +186,30 @@ connection default;
 drop user mysqltest_1@localhost;
 drop table t1;
 set global max_user_connections= @my_max_user_connections;
+#
+# End of 10.1 tests
+#
+#
+# MDEV-17852 Altered connection limits for user have no effect
+#
+create user foo@'%' with max_user_connections 1;
+connect con1,localhost,foo;
+select current_user();
+current_user()
+foo@%
+connect(localhost,foo,,test,MYSQL_PORT,MYSQL_SOCK);
+connect con2,localhost,foo;
+ERROR 42000: User 'foo' has exceeded the 'max_user_connections' resource (current value: 1)
+connection default;
+alter user foo with max_user_connections 2;
+connect con3,localhost,foo;
+select current_user();
+current_user()
+foo@%
+disconnect con3;
+disconnect con1;
+connection default;
+drop user foo@'%';
+#
+# End of 10.2 tests
+#

mysql-test/t/user_limits.test

@@ -216,3 +216,29 @@ drop table t1;
 --source include/wait_until_count_sessions.inc
 
 set global max_user_connections= @my_max_user_connections;
+
+--echo #
+--echo # End of 10.1 tests
+--echo #
+
+--echo #
+--echo # MDEV-17852 Altered connection limits for user have no effect
+--echo #
+create user foo@'%' with max_user_connections 1;
+--connect con1,localhost,foo
+select current_user();
+--replace_result $MASTER_MYPORT MYSQL_PORT $MASTER_MYSOCK MYSQL_SOCK
+--error ER_USER_LIMIT_REACHED
+--connect con2,localhost,foo
+--connection default
+alter user foo with max_user_connections 2;
+--connect con3,localhost,foo
+select current_user();
+--disconnect con3
+--disconnect con1
+--connection default
+drop user foo@'%';
+
+--echo #
+--echo # End of 10.2 tests
+--echo #

sql/sql_connect.cc

@@ -85,7 +85,6 @@ int get_or_create_user_conn(THD *thd, const char *user,
     uc->host= uc->user + user_len +  1;
     uc->len= temp_len;
     uc->connections= uc->questions= uc->updates= uc->conn_per_hour= 0;
-    uc->user_resources= *mqh;
     uc->reset_utime= thd->thr_create_utime;
     if (my_hash_insert(&hash_user_connections, (uchar*) uc))
     {
@@ -95,6 +94,7 @@ int get_or_create_user_conn(THD *thd, const char *user,
       goto end;
     }
   }
+  uc->user_resources= *mqh;
   thd->user_connect=uc;
   uc->connections++;
 end: