Wrong query results in Hive due to wrong struct nullability

CREATE TABLE `student`(
  `id` int, 
  `info` struct<name:string,age:int>)
ROW FORMAT SERDE 
  'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe' 
WITH SERDEPROPERTIES ( 
  'colelction.delim'=':', 
  'field.delim'=',', 
  'serialization.format'=',', 
  'serialization.null.format'='NULL')  

select * from student where info is not null;

1       {"name":"zhou","age":30}
2       {"name":"yan","age":30}
3       {"name":"chen","age":20}
4       {"name":"li","age":80}
NULL    NULL
NULL    {"name":null,"age":null}

HiveProject(id=[$0], info=[$1]) 
  HiveTableScan(table=[[default.student]], table:alias=[student])

HiveProject(id=[$0], info=[$1])
  HiveFilter(condition=[IS NOT NULL($1)])
    HiveTableScan(table=[[default.student]], table:alias=[student])

1 {"name":"zhou","age":30} 
2 {"name":"yan","age":30} 
3 {"name":"chen","age":20} 
4 {"name":"li","age":80}
NULL    {"name":null,"age":null}