Add test to verify count aggregate function should not be nullable

[HuSen8891]

Which issue does this PR close?

Closes #12077

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[alamb]

On main this query fails like this:

creatDataFusion CLI v41.0.0
> create table empty;
0 row(s) fetched.
Elapsed 0.008 seconds.

> select distinct count() from empty;
CombinePartialFinalAggregate
caused by
Internal error: PhysicalOptimizer rule 'CombinePartialFinalAggregate' failed, due to generate a different schema, original schema: Schema { fields: [Field { name: "count()", data_type: Int64, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: {} }], metadata: {} }, new schema: Schema { fields: [Field { name: "count()", data_type: Int64, nullable: false, dict_id: 0, dict_is_ordered: false, metadata: {} }], metadata: {} }.
This was likely caused by a bug in DataFusion's code and we would welcome that you file an bug report in our issue tracker

[alamb]

Thank you for this contribution @HuSen8891

[HuSen8891]

issue #12077 already solved, close this.

[alamb]

Thanks @HuSen8891 -- I double checked and it does seem to be fixed on main. However, I don't think we have the test.

Could you please update the PR to just have the additional test?

DataFusion CLI v41.0.0
> create table empty;
0 row(s) fetched.
Elapsed 0.007 seconds.

> select distinct count() from empty;
+---------+
| count() |
+---------+
| 0       |
+---------+
1 row(s) fetched.
Elapsed 0.010 seconds.

>

[HuSen8891]

Thanks @HuSen8891 -- I double checked and it does seem to be fixed on main. However, I don't think we have the test.

Could you please update the PR to just have the additional test?

DataFusion CLI v41.0.0
> create table empty;
0 row(s) fetched.
Elapsed 0.007 seconds.

> select distinct count() from empty;
+---------+
| count() |
+---------+
| 0       |
+---------+
1 row(s) fetched.
Elapsed 0.010 seconds.

>

Sure. Current branch is deleted, I'll add the test in another PR.

[alamb]

Sure. Current branch is deleted, I'll add the test in another PR.

PR was #12100