Bug 140620 Chart scripting errors are ignored
Write a chart with an invalid script, the execution simply ignores the script. This makes it difficult to debug scripting. The error message is also not precise and needs improvements.
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/swing/SwingRendererImpl.java
* 
	 * @see org.eclipse.birt.chart.output.IPrimitiveRenderListener#fillPolygon(org.eclipse.birt.chart.output.PolygonRenderEvent)
	 */
	public void fillPolygon( PolygonRenderEvent pre ) throws ChartException
	{
		final Fill flBackground = pre.getBackground( );
		if ( isFullTransparent( flBackground ) )
		{
			return;
		}
		final Location[] loa = pre.getPoints( );
		final int[][] i2a = getCoordinatesAsInts( loa );
		if ( flBackground instanceof ColorDefinition )
		{
			final ColorDefinition cd = (ColorDefinition) flBackground;
			_g2d.setColor( (Color) _ids.getColor( cd ) );
			_g2d.fill( new Polygon( i2a[0], i2a[1], loa.length ) );
		}
		else if ( flBackground instanceof Gradient )
		{
			final Gradient g = (Gradient) flBackground;
			final ColorDefinition cdStart = g.getStartColor( );
			final ColorDefinition cdEnd = g.getEndColor( );
			
			final double dAngleInDegrees = g.getDirection( );
			final double dAngleInRadians = ( ( -dAngleInDegrees * Math.PI ) / 180.0 );
			
			final double dMinX = BaseRenderer.getX( loa, IConstants.MIN );
			final double dMaxX = BaseRenderer.getX( loa, IConstants.MAX );
			final double dMinY = BaseRenderer.getY( loa, IConstants.MIN );