Recursive CTE should be able to infer column names without explicit column list

This query works in MySQL, PostgreSQL, SQLite, SQL Server (without recursive) but not in H2:

with recursive 
  t as (
    select 1 a
    union all
    select t.a + 1
    from t 
    where t.a < 10
  )
select * from t;

In H2, in order to reference columns from the recursive tables, they have to be declared twice:

1. In the UNION ALL query's first subquery
2. In the column list of the CTE

with recursive 
  t (a) as (
    select 1 a
    union all
    select t.a + 1
    from t 
    where t.a < 10
  )
select * from t;

That seems like an unnecessary restriction to me, given that the column name is derived correctly outside of the CTE. This works in H2 as well:

with 
  t as (
    select 1 a
  )
select a from t;

No implementation file or test is named. Start by running the recursive CTE examples against H2 and compare the behavior with the listed database systems; done means the query without an explicit CTE column list can reference its inferred column name and return the expected rows.