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
element = container;
		} while ( element != null );
		return sb.toString( );
	}
	/**
	 * Gets a string that defines the event handle class.
	 * 
	 * @return the expression as a string
	 * 
	 * @see #setEventHandlerClass(String)
	 */
	public String getEventHandlerClass( )
	{
		return getStringProperty( GroupElement.EVENT_HANDLER_CLASS_PROP );
	}
	/**
	 * Sets the group expression.
	 * 
	 * @param expr
	 *            the expression to set
	 * @throws SemanticException
	 *             If the expression is invalid.
	 * 
	 * @see #getEventHandlerClass()
	 */
	public void setEventHandlerClass( String expr ) throws SemanticException
	{
		setProperty( GroupElement.EVENT_HANDLER_CLASS_PROP, expr );
	}
	/**