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
obj = iRender.getRunTimeContext( )
						.getState( BaseRenderer.FIXED_STACKED_SERIES_LOCATION_KEY );
				if ( obj instanceof List && ( (List) obj ).size( ) > 0 )
				{
					List lst = (List) obj;
					for ( int i = 0; i < lst.size( ); i++ )
					{
						Object o = lst.get( i );
						if ( o instanceof double[] )
						{
							if ( lastFixedX == null )
							{
								lastFixedX = new double[lst.size( )];
								lastFixedY = new double[lastFixedX.length];
							}
							lastFixedX[i] = ( (double[]) o )[0];
							lastFixedY[i] = ( (double[]) o )[1];
						}
						else
						{
							lastFixedX = null;
							lastFixedY = null;
							break;
						}
					}
				}
			}
			obj = iRender.getRunTimeContext( )
					.getState( BaseRenderer.STACKED_SERIES_LOCATION_KEY );
			double[] lastX = null;