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
return;
		}
		final boolean bFirstInSequence = ( iSeriesIndex == 0 );
		final boolean bLastInSequence = ( iSeriesIndex == iSeriesCount - 1 );
		if ( bFirstInSequence )
		{
			renderBackground( ipr, p );
		}
		if ( getSeries( ) != null )
		{
			ScriptHandler.callFunction( getRunTimeContext( ).getScriptHandler( ),
					ScriptHandler.BEFORE_DRAW_SERIES,
					getSeries( ),
					this,
					getRunTimeContext( ).getScriptContext( ) );
			getRunTimeContext( ).notifyStructureChange( IStructureDefinitionListener.BEFORE_DRAW_SERIES,
					getSeries( ) );
			renderSeries( ipr, p, srh ); 
			
			ScriptHandler.callFunction( getRunTimeContext( ).getScriptHandler( ),
					ScriptHandler.AFTER_DRAW_SERIES,
					getSeries( ),
					this,
					getRunTimeContext( ).getScriptContext( ) );
			getRunTimeContext( ).notifyStructureChange( IStructureDefinitionListener.AFTER_DRAW_SERIES,
					getSeries( ) );
		}
		if ( bLastInSequence )
		{