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
loa[2].set( zeroLocation + dTapeWidth, y2
								+ kError - dTapeWidth );
						loa[3].set( zeroLocation, y2 + kError );
					}
					else
					{
						loa[2].set( x2 + kError + dTapeWidth, zeroLocation
								- dTapeWidth );
						loa[3].set( x2 + kError, zeroLocation );
					}
				}
				pre.setPoints( loa );
				if ( bDeferred )
				{
					dc.addPlane( pre, PrimitiveRenderEvent.FILL );
				}
				else
				{
					ipr.fillPolygon( pre );
				}
			}
		}
	}
	/**
	 * 
	 * @param ipr
	 * @param x1
	 * @param y1
	 * @param x2
	 * @param y2