https://clickhouse-test-reports.s3.yandex.net/21020/2ced21c837006053542b9f04c338faebf504f413/fuzzer_asan/server.log
{
    for (size_t i = starting_pos; i < block.columns(); ++i)
        convertColumnToNullable(block.getByPosition(i));
}
void removeColumnNullability(ColumnWithTypeAndName & column)
{
    if (!column.type->isNullable())
        return;
    column.type = static_cast<const DataTypeNullable &>(*column.type).getNestedType();
    if (column.column)
    {
        const auto * nullable_column = checkAndGetColumn<ColumnNullable>(*column.column);
        ColumnPtr nested_column = nullable_column->getNestedColumnPtr();
        MutableColumnPtr mutable_column = IColumn::mutate(std::move(nested_column));
        column.column = std::move(mutable_column);
    }
}
void changeColumnRepresentation(const ColumnPtr & src_column, ColumnPtr & dst_column)
{
    bool nullable_src = src_column->isNullable();
    bool nullable_dst = dst_column->isNullable();
    ColumnPtr dst_not_null = JoinCommon::emptyNotNullableClone(dst_column);
    bool lowcard_src = JoinCommon::emptyNotNullableClone(src_column)->lowCardinality();
    bool lowcard_dst = dst_not_null->lowCardinality();
    bool change_lowcard = (!lowcard_src && lowcard_dst) || (lowcard_src && !lowcard_dst);
    if (nullable_src && !nullable_dst)
    {