**How to reproduce**

Query:
```sql
select
	x,
	min(x) as lower,
	max(x)+1 as upper,
	upper-lower as range
from (select arrayJoin([1, 2]) as x)
group by x
with rollup;
```

## 20.4.6
```
┌─x─┬─lower─┬─upper─┬─range─┐
│ 1 │     1 │     2 │     1 │
│ 2 │     2 │     3 │     1 │
└───┴───────┴───────┴───────┘
┌─x─┬─lower─┬─upper─┬─range─┐
│ 0 │     1 │     3 │     2 │
└───┴───────┴───────┴───────┘
```
Summary looks correct.

## 20.9.3
```
┌─x─┬─lower─┬─upper─┬─range─┐
│ 1 │     1 │     2 │     1 │
│ 2 │     2 │     3 │     1 │
└───┴───────┴───────┴───────┘
┌─x─┬─lower─┬─upper─┬─range─┐
│ 0 │     0 │     3 │     2 │
└───┴───────┴───────┴───────┘
```
`lower` is wrong - the minimum should be 1. However, all other "derived" values are correct. For example `range` correctly shows up as 2, even though table would wrongly imply that `upper-lower==3-0==3`.
Note that I only tested 20.4.6 and 20.9.3, so the regression might have been anywhere in between.

## 20.10.2
```
┌─x─┬─lower─┬─upper─┬─range─┐
│ 1 │     1 │     2 │     1 │
│ 2 │     2 │     3 │     1 │
└───┴───────┴───────┴───────┘
┌─x─┬─lower─┬─upper─┬─range─┐
│ 0 │     0 │     1 │     1 │
└───┴───────┴───────┴───────┘
```
All values are wrong.
{
    
    UInt64 unused_column = 0;
    String unused_column_name = toString(unused_column);
    while (source_columns.count(unused_column_name))
    {
        ++unused_column;
        unused_column_name = toString(unused_column);
    }
    select_query->setExpression(ASTSelectQuery::Expression::GROUP_BY, std::make_shared<ASTExpressionList>());
    select_query->groupBy()->children.emplace_back(std::make_shared<ASTLiteral>(UInt64(unused_column)));
}
void optimizeGroupBy(ASTSelectQuery * select_query, const NameSet & source_columns, const Context & context)