<class name="test.baz.bar.Foo" table="foo">
  <id name="id" column="fid">
    <generator class="assigned"/>
  </id>
  <property name="barId" type="integer"/>
</class>

1) Caret is on "Foo", inside attribute "name" of element <class>. Refactor->Rename is invoked.
2) IDEA asks

Class 'Foo' belongs to Persistent Object Model Helper 'Foo'
Do you want to rename Persistent Object Model Helper 'Foo' instead?
[Yes] [No]

We choose "No", we want to rename the real Java class. Next, we choose "Wolf" as the new class name.
3) Class is properly renamed, however, a class-level annotation is added:

@javax.persistence.Entity(name = "Foo")
public class Wolf {
    // ...
}

Some thoughts:

• obviously usage of "javax.persistence.Entity" annotation is wrong, since I'm just using plain Hibernate3 (I don't even have this annotation class in my classpath)
• the "correct variation" of current behavior would be to add an "entity-name" attribute to the <class> element inside the .hbm.xml file.

However, the majority of Hibernate projects does not use explicit entity names.
In such situations, the user wants to rename the Java class, and expects usages in HQL etc to automatically be included.

For a more detailed proposal to simplify this, see IDEA-12790.