Fail merge

[lisandrofernandez]

This test fails because an org.hibernate.TransientObjectException is thrown when calling post.getComments().isEmpty() with a merge operation.

A couple of things to mention:

• Although calling isEmpty() is useless here, it serves as a testing propose. Deleting this call avoids the exception.
• Retrieving the post along with its comments using a "LEFT JOIN FETCH" query not only avoids the exception but also is better in terms of performance.
• Calling entityManager.persist(post) instead of entityManager.merge(post) also avoids the exception. In fact, both calls are redundant since the post is being managed by the current running Persistence Context.

[vladmihalcea]

@lisandrofernandez I checked it out, and it's a Hibernate bug. You need to open a Jira issue and attache a replicating test case.

It looks like the merge generates an extra copy of the transient entity which has an id of null as if it was loaded from the DB.

I think @gbadner is the best person to tackle this issue.

[lisandrofernandez]

@vladmihalcea I opened HHH-13815 to track the issue. I also opened a pull request with a replicated test case.

[vladmihalcea]

Great.