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
private final int iNumberOfPoints;
		private final double[] fa;
		private final double[] faA;
		private final double[] faB;
		private final double[] faC;
		/**
		 * 
		 * @param _fa
		 */
		public Spline( double[] _fa )
		{
			iNumberOfPoints = _fa.length;
			fa = new double[iNumberOfPoints];
			faA = new double[iNumberOfPoints - 1];
			faB = new double[iNumberOfPoints - 1];
			faC = new double[iNumberOfPoints - 1];
			for ( int i = 0; i < iNumberOfPoints; i++ )
			{
				fa[i] = _fa[i];
			}
			computeCoefficients( );
		}
		private final void computeCoefficients( )
		{
			double p, dy1, dy2;
			dy1 = fa[1] - fa[0];
			for ( int i = 1; i < iNumberOfPoints - 1; i++ )
			{
				dy2 = fa[i + 1] - fa[i];
				faC[i] = 0.5f;