Bug 151959 inappropriate screen operation
steps to reproduce: - create a report - add a grid item (3x3) - switch to Outline view - expand the grid item to see its rows and cells - select the grid item, and drag it into any of its own cell expected behavior: - is it an invalid screen operation? if it is, it should be banned actual behavior: - the grid item was disappeared surprisingly
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* elements are not copied.
	 * 
	 * @param module
	 *            the module
	 * 
	 * @return <code>true</code> if the refresh action is successful.
	 *         <code>false</code> othersize.
	 * 
	 */
	public boolean refreshStructureFromParent( Module module )
	{
		DesignElement parent = getExtendsElement( );
		if ( parent == null )
			return false;
		
		return ElementStructureUtil.updateStructureFromParent( this, parent );
	}
	/**
	 * Resolve and returns the virtual parent element. If the element is not
	 * virtual element, <code>null</code> will be returned. Otherwise, find
	 * and returns the virtual parent using the <code>baseId</code>.
	 * 
	 * @return the virtual parent element.
	 */
	public DesignElement getVirtualParent( )
	{
		if ( !isVirtualElement( ) )
			return null;
		
		DesignElement parent = null;