Bug 176582 "Show Lines as Curves" does not work correctly for Area Chart [0001]
Description: "Show Lines as Curves" does not work correctly for Area Chart. Build number: 2.2.0.v20070307-1128 Steps to reproduce: 1. New a Area Chart. 2. In "Format Chart" tab, select Series->Value (Y) Series, tick and untick "Show Lines as Curves" checkbox. Expected result: Null value point e is treated the same when tick and untick "Show Lines as Curves" checkbox. Actual result: Null value point e is treated differently (see the screenshot). Error log: N/A
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/CurveRenderer.java
loa3d[0].set( pt0[0], zeroLocation, pt0[2] );
			loa3d[1].set( pt0[0], zeroLocation, pt0[2] - dTapeWidth );
			loa3d[2].set( pte[0], zeroLocation, pte[2] - dTapeWidth );
			loa3d[3].set( pte[0], zeroLocation, pte[2] );
			pre3d.setPoints3D( loa3d );
			dc.addPlane( pre3d, PrimitiveRenderEvent.FILL );
			if ( lia.isSetVisible( ) && lia.isVisible( ) && points.size( ) > 1 )
			{
				double[] ptp = (double[]) points.get( 0 );
				for ( int i = 1; i < points.size( ); i++ )
				{
					double[] pta = (double[]) points.get( i );
					lre3d.setStart3D( ptp[0], ptp[1], ptp[2] );
					lre3d.setEnd3D( pta[0], pta[1], pta[2] );
					ptp = pta;
					dc.addLine( lre3d );
				}
			}
		}
		else
		{
			Location[] pa = new Location[points.size( ) + 2];
			for ( int i = 0; i < points.size( ); i++ )
			{
				double[] pt = (double[]) points.get( i );
				pa[i] = LocationImpl.create( pt[0], pt[1] );
			}
			if ( cwa.isTransposed( ) )
			{
				pa[pa.length - 2] = LocationImpl.create( zeroLocation,