title: Is it possible to user @JsonIdentityInfo with ObjectIdGenerators.PropertyGenerator when the IDs from different entity types overlap?
body: <p><strong>Is it possible to user @JsonIdentityInfo with ObjectIdGenerators.PropertyGenerator when the IDs from different entity types overlap?</strong></p>
  
  <p>Assume that I have the following XML and want to deserialize it with Jackson 2.x:</p>
  
  <pre><code>&lt;foo&gt;
    &lt;id&gt;3&lt;/id&gt;
    &lt;name&gt;Peter&lt;/name&gt;
    &lt;bar&gt;
       &lt;id&gt;3&lt;/id&gt;
       &lt;kind&gt;dog&lt;/kind&gt;
       &lt;!--belongsTo&gt;3&lt;/belongsTo--&gt;
    &lt;/bar&gt;
  &lt;/foo&gt;
  </code></pre>
  
  <p>I've annotated the Foo and Bar class with <code>@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")</code>.</p>
  
  <p>The deserialization fails with <code>com.fasterxml.jackson.databind.JsonMappingException: Already had POJO for id (java.lang.String) [3]</code>.</p>
  
  <p>If bar has the id 4, everything works fine.</p>
  
  <p>What are the requirements regarding the IDs in XML to be deserialized by Jackson? I have assumed that - since Jackson knows to which entity scope it would be able to work with the same id as long as it belongs to different types. </p>
  
  <p>P.S.: It doesn't seem to matter the belongsTo reference (pointing to a foo object) is set or not.</p>