https://clickhouse-test-reports.s3.yandex.net/17375/99073c26ee2692f8efe2ab14b2d8ae0fd813b80e/fuzzer/fuzzer.log

```
SELECT
    k,
    topK(v)
FROM 
(
    SELECT
        number % 7 AS k,
        arrayMap(x -> arrayMap(x -> if(x = 0, NULL, toString(x)), range(x)), range(intDiv(number, 1))) AS v
    FROM system.numbers
    LIMIT 257
)
GROUP BY k
ORDER BY k ASC
```
{
        Cell::State::writeText(wb);
        DB::writeText(m_size, wb);
        if (this->hasZero())
        {
            DB::writeChar(',', wb);
            this->zeroValue()->writeText(wb);
        }
        if (!buf)
            return;
        for (auto ptr = buf, buf_end = buf + grower.bufSize(); ptr < buf_end; ++ptr)
        {
            if (!ptr->isZero(*this))
            {
                DB::writeChar(',', wb);
                ptr->writeText(wb);
            }
        }
    }
    void read(DB::ReadBuffer & rb)