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/BaseRenderer.java
* 
	 * @throws ChartException
	 */
	protected void renderBlock( IPrimitiveRenderer ipr, Block b, Object oSource )
			throws ChartException
	{
		final double dScale = getDeviceScale( );
		final RectangleRenderEvent rre = (RectangleRenderEvent) ( (EventObjectCache) ipr ).getEventObject( oSource,
				RectangleRenderEvent.class );
		rre.updateFrom( b, dScale );
		ipr.fillRectangle( rre );
		ipr.drawRectangle( rre );
	}
	/**
	 * Renders the chart block.
	 * 
	 * @param ipr
	 * @param b
	 * 
	 * @throws ChartException
	 */
	protected void renderChartBlock( IPrimitiveRenderer ipr, Block b,
			Object oSource ) throws ChartException
	{
		final double dScale = getDeviceScale( );
		final RectangleRenderEvent rre = (RectangleRenderEvent) ( (EventObjectCache) ipr ).getEventObject( oSource,
				RectangleRenderEvent.class );
		rre.updateFrom( b, dScale );
		ipr.fillRectangle( rre );
		ipr.drawRectangle( rre );