[news.eclipse.modeling.mdt.uml2] Problems with DerivedUnion during deser

[Timothy Marc <timothymarc@xxxxxxxxxx>]

Hey all,

i'm using the UML2 genmodel to generate a uml-like metamodel with 
subsets and unions etc. I've rebuild the Element -> ownedComment 
relationship of the UML 2.2 Superstructure (Figure 7.3). Instead of 
Comment, i've sed the term Annotation. The model looks like

Element {abstract}
	+/owner 0..1 {union, read-only}
	+/ownedElement * {union, read-only}

TestingModel extends Element
	+ annotation * {subsets ownedElement}

Annotation extends Element


When i define a simple model like the model mentioned in the following 
XMI snippet

<?xml version="1.0" encoding="UTF-8"?>
<union:TestingModel xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI"; 
xmlns:union="http:///union.ecore"; ownedElement="//@annotation.0">
  <annotation/>
</union:TestingModel>

i ran allways in an exception during deserialization. I've tried both 
the editor and the programmatically deserialization. Both fail with the 
following exception trace. It seems, that somewhere the 
DerivedEObjectEList.add() method will be called.

org.eclipse.emf.ecore.xmi.IllegalValueException: Value 
'union.impl.AnnotationImpl@352d87' is not legal. 
(platform:/resource/f/My.union, -1, -1)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLHandler.setFeatureValue(XMLHandler.java:2648)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLHandler.handleForwardReferences(XMLHandler.java:1135)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLHandler.endDocument(XMLHandler.java:1214)
	at 
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endDocument(Unknown 
Source)
	at 
com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown 
Source)
	at 
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown 
Source)
	at 
com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown 
Source)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown 
Source)
	at 
com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown 
Source)
	at 
com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown 
Source)
	at javax.xml.parsers.SAXParser.parse(Unknown Source)
	at org.eclipse.emf.ecore.xmi.impl.XMLLoadImpl.load(XMLLoadImpl.java:181)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLResourceImpl.doLoad(XMLResourceImpl.java:180)
	at 
org.eclipse.emf.ecore.resource.impl.ResourceImpl.load(ResourceImpl.java:1445)
	at 
org.eclipse.emf.ecore.resource.impl.ResourceImpl.load(ResourceImpl.java:1241)
	at 
org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.demandLoad(ResourceSetImpl.java:255)
	at 
org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.demandLoadHelper(ResourceSetImpl.java:270)
	at 
org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.getResource(ResourceSetImpl.java:397)
	at union.presentation.UnionEditor.createModel(UnionEditor.java:950)
	at union.presentation.UnionEditor.createPages(UnionEditor.java:1007)
	at 
org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:310)
	at ....


Caused by: java.lang.UnsupportedOperationException
	at 
org.eclipse.uml2.common.util.DerivedEObjectEList$DerivedListIterator.add(DerivedEObjectEList.java:278)
	at java.util.AbstractSequentialList.add(Unknown Source)
	at 
org.eclipse.uml2.common.util.DerivedEObjectEList.addUnique(DerivedEObjectEList.java:636)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLHelperImpl.setValue(XMLHelperImpl.java:1192)
	at 
org.eclipse.emf.ecore.xmi.impl.XMLHandler.setFeatureValue(XMLHandler.java:2643)
	... 58 more


For serialization and deserialization i'm using an XMIBResource(Factory) 
created by the genmodel automatically. Please let me know, what is going 
wrong in this really simple example.

Thanks in advance
Timothy