**Describe what's wrong**

```sql
SELECT toTypeName(s), toString(s) FROM
(
 SELECT toFixedString('',32) AS s 
 UNION ALL
 SELECT null AS s 
)
```

this query works in all versions from 19.17 to 21.8, but stop works after 21.9+ 

https://fiddle.clickhouse.com/7bd65b36-a6e6-470a-8bdc-4c98a33ff453
21.8 works

https://fiddle.clickhouse.com/9e40a424-4027-4c7f-bd41-b20935ae9129
21.9 doesn't work
```
Received exception from server (version 21.9.6):
Code: 44. DB::Exception: Received from localhost:9000. DB::Exception: Illegal column Nullable(FixedString(32)) of first argument of function toString. (ILLEGAL_COLUMN)
```

this query works in all versions

```sql
SELECT toTypeName(s), toString(s) FROM
(
 SELECT '' AS s 
 UNION ALL
 SELECT null AS s 
)
```
https://fiddle.clickhouse.com/4f810f03-1644-4eb7-b696-0341b1bbdbc4


**Does it reproduce on recent release?**
Yes, reproduce in all releases 21.9+
{
    DayNum tmp(0);
    if (!tryReadDateText(tmp, rb))
        return false;
    x = tmp;
    return true;
}
template <>
inline bool tryParseImpl<DataTypeDate32>(DataTypeDate32::FieldType & x, ReadBuffer & rb, const DateLUTImpl *)
{
    ExtendedDayNum tmp(0);
    if (!tryReadDateText(tmp, rb))
        return false;
    x = tmp;
    return true;
}
template <>
inline bool tryParseImpl<DataTypeDateTime>(DataTypeDateTime::FieldType & x, ReadBuffer & rb, const DateLUTImpl * time_zone)
{
    time_t tmp = 0;
    if (!tryReadDateTimeText(tmp, rb, *time_zone))
        return false;
    x = tmp;
    return true;
}
template <>
inline bool tryParseImpl<DataTypeUUID>(DataTypeUUID::FieldType & x, ReadBuffer & rb, const DateLUTImpl *)