We use a multi-column unique constraint and a version tag for optimistic locking. For some columns we want to detect changes and generate entries in other table.

So the setup is following:
*.hbm.xml

  <class name="anyClass" table="any_class">
    <id name="id" column="id" type="long" unsaved-value="0">
    </id>
    <version type="timestamp" column="changed" name="changed" access="property" unsaved-value="null" />
    <properties name="uniqueConst" unique="true">
      <property name="first" type="string" length="70" />
      <property name="secound" column="secound" type="string" length="25" />
    </properties>
    <property name="normalProp" column="normal" type="string" length="25"/>
</class>

And we register and implement a PreUpdateEventListener. This listener will compare old and new values. And will create a new record for every change.

We achive this by getting the state via:

Object old = ((PreUpdateEvent)inEvent).getOldState();
Object new = ((PreUpdateEvent)inEvent).getState();}}

So our testcase:

AnyClass any = ourDao.getAnyClass();
any.setFirst("blabla");
assertEquals(2, ourDao().listAudit().size());

In Hibernate 4.3.11 we get 2 changes.
In Hibernate 5.0.7 we get 1 change.

So what happens? One change cannot be detected, because our timestamp property only changes in Hibernate 4.3.11? But if we touch normalProp everything works as expected. I assume changes in a property grouped by properties aren't detected, resp. the dirty flag isn't set.