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
{
			displayLabel = getNameForDisplayLabel( );
		}
		if ( level == USER_LABEL )
		{
			return displayLabel;
		}
		MetaDataDictionary dictionary = MetaDataDictionary.getInstance( );
		IElementDefn elementDefn = dictionary.getElement( getElementName( ) );
		if ( StringUtil.isBlank( displayLabel ) )
		{
			displayLabel = elementDefn.getDisplayName( );
		}
		if ( StringUtil.isBlank( displayLabel ) )
		{
			displayLabel = elementDefn.getName( );
		}
		return displayLabel;
	}
	/**
	 * Returns the name of this element for display label.
	 * 
	 * @return the name of this element for display label.
	 */
	protected String getNameForDisplayLabel( )
	{
		return getName( );
	}
	/**
	 * All descriptive text should be "elided" to a length of 30 characters. To