title: Hibernate Envers: I'm getting nulls in a List when loading a revision
body: <p>I have an object "Foo" that contains a list of other objects "Bar".  If I load up a revision of Foo, I get my correctly ordered list of Bars - however I also get a number of nulls.  If I look at the audit table that holds the bars I see something like this on the initial object save:</p>
  
  <pre><code>    id   | rev  | revtype |    create_timestamp     |    update_timestamp     | updated_by_id | created_by_id | foo_id                | bar_index     | bar_value
     ------+------+---------+-------------------------+-------------------------+---------------+---------------+-----------------------+---------------+-----------
      1000 | 1000 |       0 | 2018-09-28 12:26:48.49  | 2018-09-28 12:26:48.49  |             1 |             1 |                       |               | ValueA    
      1001 | 1000 |       0 | 2018-09-28 12:26:48.49  | 2018-09-28 12:26:48.49  |             1 |             1 |                       |               | ValueB    
      1000 | 1000 |       0 |                         |                         |               |               |                  1000 |             0 |           
      1001 | 1000 |       0 |                         |                         |               |               |                  1000 |             1 |           
  </code></pre>
  
  <p>So then in the future I want to grab Foo which has Revision 1000 for the Bars I end up with 2 nulls and my two values.  Seeing that table I'm not totally surprised.  If feels like a bug with how Lists are processed, if I change it to a set it works fine (So I guess I could leave it as a set, then populate the index column myself and sort it myself when loaded - but that isn't great for an object hierarchy and a lot of lists) But I could just be missing something in how I'm doing things.  </p>
  
  <p>Mapping in Bar:</p>
  
  <pre><code>    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
      @JoinColumn(name = "foo_id")
      @OrderColumn(name = "bar_index")
      private List&lt;Bar&gt; bars = new ArrayList&lt;&gt;();
  </code></pre>
  
  <p>Any thoughts on how to make this work without getting nulls in the loaded list?  Is it an Envers bug, Hibernate bug, user error?  Thanks!</p>