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
return propValues.get( prop.getName( ) );
	}
	/**
	 * Returns the value of an intrinsic property. Derived classes should
	 * override this to handle their own intrinsics. Clients should call the
	 * getProperty( ) or getLocalProperty( ) methods instead of calling this
	 * method directly.
	 * 
	 * @param propName
	 *            name of the intrinsic
	 * @return the value of the requested property
	 */
	protected Object getIntrinsicProperty( String propName )
	{
		if ( NAME_PROP.equals( propName ) )
			return name;
		if ( EXTENDS_PROP.equals( propName ) )
		{
			if ( extendsRef != null && !extendsRef.isResolved( ) )
				resolveExtends( getRoot( ) );
			return extendsRef;
		}
		assert false;
		return null;
	}
	/**
	 * Sets the value of an intrinsic property. This should be called only from
	 * a command or the design parser. The property name must be valid, and the
	 * value must be valid for that property.