Bug 163018 An error extension will lead the report contain chart can't be opened and can not new a report.
Details: An error extension will lead the report contain chart can't open In org.eclipse.birt.report.tests.model has an error extension. When run the birt use workbenck, the report contain chart can't be opened and it can not new a report.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
Iterator iter = triggerDefns.iterator( );
		while ( iter.hasNext( ) )
		{
			SemanticTriggerDefn triggerDefn = (SemanticTriggerDefn) iter.next( );
			String targetName = triggerDefn.getTargetElement( );
			if ( StringUtil.isBlank( targetName ) )
			{
				getTriggerDefnSet( ).add( triggerDefn );
			}
			else
			{
				ElementDefn targetDefn = (ElementDefn) MetaDataDictionary
						.getInstance( ).getElement( targetName );
				if ( isKindOf( targetDefn ) )
				{
					getTriggerDefnSet( ).add( triggerDefn );
				}
			}
		}
	}
	/**
	 * Checks the xml name for this element. Check the xml name is not empty and
	 * unique.
	 * 
	 * @throws MetaDataException
	 *             if the xml name of this element is not defined or not unique
	 */
	private void checkXmlName( ) throws MetaDataException
	{
		if ( StringUtil.isBlank( xmlName ) )