https://clickhouse-test-reports.s3.yandex.net/21020/2ced21c837006053542b9f04c338faebf504f413/fuzzer_asan/server.log
{
    if (!column_indices_right.count(right_pos))
    {
        column_indices_right[right_pos] = result_position;
        extractColumnChanges(right_pos, result_position);
    }
    else
        same_result_keys[result_position] = column_indices_right[right_pos];
}
void NotJoined::extractColumnChanges(size_t right_pos, size_t result_pos)
{
    const auto & src = saved_block_sample.getByPosition(right_pos).column;
    const auto & dst = result_sample_block.getByPosition(result_pos).column;
    if (!src->isNullable() && dst->isNullable())
        right_nullability_adds.push_back(right_pos);
    if (src->isNullable() && !dst->isNullable())
        right_nullability_removes.push_back(right_pos);
    ColumnPtr src_not_null = JoinCommon::emptyNotNullableClone(src);
    ColumnPtr dst_not_null = JoinCommon::emptyNotNullableClone(dst);
    if (src_not_null->lowCardinality() != dst_not_null->lowCardinality())
        right_lowcard_changes.push_back({right_pos, dst_not_null});
}
void NotJoined::correctLowcardAndNullability(MutableColumns & columns_right)