Luis Barreiro, I have changed my demo project to use the 5.2.1-SNAPSHOT versions by applying HHH-10865-3.diff.

At the time of writing, the snapshot versions were hibernate-core-5.2.1-20160628.131959-62 and hibernate-enhance-maven-plugin-5.2.1-20160628.132014-61.

Unfortunately, the issue is still present: mvn clean test still prints

Hibernate: delete from parents_children where parent=?

and

java.lang.RuntimeException: Child count is 0. Child hasn't been added to parent?!