java.lang.NullPointerException
	at org.eclipse.jpt.common.utility.internal.CollectionTools.addAll(CollectionTools.java:50)
	at org.eclipse.jpt.jpa.ui.internal.JpaXmlCompletionProposalComputer.getProposedValues(JpaXmlCompletionProposalComputer.java:182)
	at org.eclipse.jpt.jpa.ui.internal.JpaXmlCompletionProposalComputer.addAttributeValueProposals(JpaXmlCompletionProposalComputer.java:73)
	at org.eclipse.jpt.jpa.ui.internal.AbstractJpaXmlCompletionProposalComputer.computeAttributeValueProposals(AbstractJpaXmlCompletionProposalComputer.java:569)
	at org.eclipse.jpt.jpa.ui.internal.AbstractJpaXmlCompletionProposalComputer.computeCompletionProposals(AbstractJpaXmlCompletionProposalComputer.java:386)
	at org.eclipse.jpt.jpa.ui.internal.AbstractJpaXmlCompletionProposalComputer.computeCompletionProposals(AbstractJpaXmlCompletionProposalComputer.java:159)
	at org.eclipse.jpt.jpa.ui.internal.JpaXmlCompletionProposalComputer.computeCompletionProposals(JpaXmlCompletionProposalComputer.java:58)
	at org.eclipse.wst.sse.ui.internal.contentassist.CompletionProposalComputerDescriptor.computeCompletionProposals(CompletionProposalComputerDescriptor.java:284)
	at org.eclipse.wst.sse.ui.internal.contentassist.CompletionProposalCategory.computeCompletionProposals(CompletionProposalCategory.java:294)
	at org.eclipse.wst.sse.ui.contentassist.StructuredContentAssistProcessor.collectProposals(StructuredContentAssistProcessor.java:475)
	at org.eclipse.wst.sse.ui.contentassist.StructuredContentAssistProcessor.computeCompletionProposals(StructuredContentAssistProcessor.java:254)
	at org.eclipse.wst.sse.ui.internal.contentassist.CompoundContentAssistProcessor.computeCompletionProposals(CompoundContentAssistProcessor.java:127)
	at org.eclipse.jface.text.contentassist.ContentAssistant.computeCompletionProposals(ContentAssistant.java:1839)