Subquery in 'where' clause causes additional 'join' creation in SQM

When you create a subquery on entity which is joined then additional inner join is created in SQM query.

Entities:

Query creation:

In the first query we receive following result:

There’s the additional inner join to c2_0, which is never used.

In the second query this is the result:

There are not additional joins.

First query with Hibernate 5.6.15:

It doesn’t have any additional inner join.

Test case -

I have created same test case in orm-5 and orm-6. In orm-5 it works and it fails in orm-6.