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
&& defn.isKindOf( MetaDataDictionary.getInstance( ).getElement(
						ReportDesignConstants.TEMPLATE_ELEMENT ) ) )
		{
			
			
			DesignElement container = this;
			int slot = slotID;
			while ( container != null )
			{
				if ( ( container instanceof Module && slot == Module.COMPONENT_SLOT )
						|| container instanceof Library )
					return false;
				slot = container.getContainerSlot( );
				container = container.getContainer( );
			}
			if ( module instanceof Library )
				return false;
		}
		return true;
	}
	/**
	 * Checks whether the <code>content</code> can be inserted to the slot
	 * <code>slotId</code> in another element <code>container</code>.
	 * 
	 * @param module
	 *            the module
	 * @param container
	 *            the container element
	 * @param slotId
	 *            the slot id of the container element