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
*            the module
	 * @param slotId
	 *            the slot id
	 * @param element
	 *            the element to insert
	 * @return a list containing exceptions.
	 */
	public final List checkContainmentContext( Module module, int slotId,
			DesignElement element )
	{
		boolean retValue = canContainInRom( slotId, element.getDefn( ) );
		ContentException e = new ContentException( this, slotId, element,
				ContentException.DESIGN_EXCEPTION_INVALID_CONTEXT_CONTAINMENT );
		List errors = new ArrayList( );
		if ( !retValue )
		{
			errors.add( e );
			return errors;
		}
		
		
		
		
		
		if ( !canContainTemplateElement( module, slotId, element ) )
		{
			errors.add( e );
			return errors;
		}