https://s3.amazonaws.com/clickhouse-test-reports/42778/66c179217cdfdee1ba0d4b4b577b1a62655caed0/fuzzer_astfuzzermsan//report.html

Minimal example
```sql
#!/usr/bin/clickhouse-client --queries-file

DROP TABLE IF EXISTS tab1;
DROP TABLE IF EXISTS tab2;

SET allow_suspicious_low_cardinality_types = 1;

create table tab1 (a1 Int32, b1 Int32) engine = MergeTree order by a1;
create table tab2 (a2 LowCardinality(Int32), b2 Int32) engine = MergeTree order by a2;

insert into tab1 values (1, 2);
insert into tab2 values (1, 2);

SET join_use_nulls = 1;

SELECT 1 FROM tab1 FULL OUTER JOIN tab2 ON b1 - 2 = a2 OR a1 = b2;

```
{
        if (!nulls_position.has_value())
            nulls_position = parent.data->blocks_nullmaps.begin();
        auto end = parent.data->blocks_nullmaps.end();
        for (auto & it = *nulls_position; it != end && rows_added < max_block_size; ++it)
        {
            const auto * block = it->first;
            ConstNullMapPtr nullmap = nullptr;
            if (it->second)
                nullmap = &assert_cast<const ColumnUInt8 &>(*it->second).getData();
            for (size_t row = 0; row < block->rows(); ++row)
            {
                if (nullmap && (*nullmap)[row])
                {
                    for (size_t col = 0; col < columns_keys_and_right.size(); ++col)
                        columns_keys_and_right[col]->insertFrom(*block->getByPosition(col).column, row);
                    ++rows_added;
                }
            }
        }
    }
};
std::shared_ptr<NotJoinedBlocks> HashJoin::getNonJoinedBlocks(const Block & left_sample_block,