bug: query result not correct

[zhenglin-charlie-li]

Have you read the Contributing Guidelines on issues?

• [X] I have read the Contributing Guidelines on issues.

Please confirm if bug report does NOT exists already ?

• [X] I confirm there is no existing issue for this

Describe the problem

SQLancer found that the query below result is not correct on docker v1.0.4, though correct result on docker v1.0.3

Expected behavior

both two select return NULL

How To Reproduce

CREATE TABLE t0(c0 INT);
SELECT * FROM t0 WHERE (t0.c0 IS NULL); 
SELECT SUM(count) FROM (SELECT (t0.c0 IS NULL) IS TRUE  as count FROM t0) as res; -- Expted NULL but got 1
SELECT SUM(count) FROM (SELECT CAST((t0.c0 IS NULL) AS UNSIGNED)  as count FROM t0) as res;  -- Expted NULL but got 1

Environment

docker v1.0.4

Are you interested in submitting a PR to solve the problem?

• [ ] Yes, I will!

[Double0101]

In the function AggregationAlgorithm::Aggregate in aggregation_algorithm.cpp, it doesn't check validity of mit before PutAggregatedValue.

void AggregationAlgorithm::Aggregate(bool just_distinct, int64_t &limit, int64_t &offset, ResultSender *sender) {
  MEASURE_FET("TempTable::Aggregate(...)");
  thd_proc_info(m_conn->Thd(), "aggregation");
......
  {
      for (int gr_a = gbw.NumOfGroupingAttrs(); gr_a < gbw.NumOfAttrs(); gr_a++) {
        TempTable::Attr &cur_a = *(t->GetAttrP(gr_a));

        if (cur_a.term.vc && dynamic_cast<Tianmu::vcolumn::ExpressionColumn *>(cur_a.term.vc)) {
          bool value_successfully_aggregated = gbw.PutAggregatedValue(gr_a, 0, mit, mit.Factor());
          if (!value_successfully_aggregated) {
            gbw.DistinctlyOmitted(gr_a, 0);
          }
        }
      }
    }
  } 
......
}