Bug 142928 Item from library is changed to a report design item after revert to report item
Details: Item from library is changed to a report design item after revert to report item. Setp: 1.New a template. 2.Use a libary contain a label. 3.Drop the label from library explorer into layout. 4.Change the label to template item. 5.Revert the template item to report item. Actual result: The label is become a report item, but a item from library. Please see the attach image. Exception result: The lable is revert a item from library.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
public Iterator derivedIterator( )
	{
		return new DerivedElementIterator( module, this );
	}
	/**
	 * Returns an iterator over the clients of this element. Useful only for
	 * styles. Returns a list of all the elements that use this style.
	 * 
	 * @return an iterator over the clients of this element. Each item returned
	 *         by the iterator's <code>getNext( )</code> method is of type
	 *         {@link DesignElementHandle}. Nothing will be iterated over an
	 *         element that is not <code>ReferenceableElement</code>.
	 */
	public Iterator clientsIterator( )
	{
		return new ClientIterator( this );
	}
	/**
	 * Returns a array of valid choices for a property.
	 * 
	 * @param propName
	 *            the property name
	 * @return a array containing choices for the given property. Return
	 *         <code>null</code>, if this property has no choice.
	 */
	public IChoice[] getChoices( String propName )
	{
		PropertyHandle propertyHandle = getPropertyHandle( propName );
		if ( propertyHandle == null )
			return null;