Hi,

if I create a mixin, remove it and create it afterwards again, I get an NPE.

Note that while I use a single session in this example, the exception is also thrown if I use different sessions.

{code}
        Session adminSession = createSession("admin", "admin", "repository", "default");
        NodeTypeManager ntmgr = adminSession.getWorkspace().getNodeTypeManager();
        NodeTypeTemplate ndt = ntmgr.createNodeTypeTemplate();
        // create mixin
        ndt.setMixin(true);                                
        ndt.setName("dmsmix:test");
        ndt.setQueryable(true);                        
        ntmgr.registerNodeType(ndt, true);
 
        // remove it 
        ntmgr.unregisterNodeType("dmsmix:test");        
 
        // create one with same name again                        
        ndt = ntmgr.createNodeTypeTemplate();        
        ndt.setMixin(true);                                
        ndt.setName("dmsmix:test");
        ndt.setQueryable(true);    
        ntmgr.registerNodeType(ndt, true);  // fails !!!
{code}

Stacktrace:

{code}
java.lang.NullPointerException
    at org.modeshape.jcr.cache.document.SessionNode.updateReferences(SessionNode.java:768)
    at org.modeshape.jcr.cache.document.SessionNode.setProperties(SessionNode.java:897)
    at org.modeshape.jcr.SystemContent.store(SystemContent.java:315)
    at org.modeshape.jcr.SystemContent.store(SystemContent.java:256)
    at org.modeshape.jcr.RepositoryNodeTypeManager.registerNodeTypes(RepositoryNodeTypeManager.java:516)
    at org.modeshape.jcr.RepositoryNodeTypeManager.registerNodeType(RepositoryNodeTypeManager.java:377)
    at org.modeshape.jcr.JcrNodeTypeManager.registerNodeType(JcrNodeTypeManager.java:489)
{code}

What causes this issue?

Thanks, Niels