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.swt/src/org/eclipse/birt/chart/device/swt/SwtRendererImpl.java
Path pt = new Path( ( (SwtDisplayServer) _ids ).getDevice( ) );
					if ( are.getStyle( ) == ArcRenderEvent.CLOSED )
					{
						pt.addArc( (float) ( ( are.getTopLeft( ).getX( ) + dTranslateX ) * dScale ),
								(float) ( ( are.getTopLeft( ).getY( ) + dTranslateY ) * dScale ),
								(float) ( are.getWidth( ) * dScale ),
								(float) ( are.getHeight( ) * dScale ),
								(float) are.getStartAngle( ),
								(float) are.getAngleExtent( ) );
						pt.lineTo( (float) xs, (float) ys );
					}
					else if ( are.getStyle( ) == ArcRenderEvent.SECTOR )
					{
						pt.addArc( (float) ( ( are.getTopLeft( ).getX( ) + dTranslateX ) * dScale ),
								(float) ( ( are.getTopLeft( ).getY( ) + dTranslateY ) * dScale ),
								(float) ( are.getWidth( ) * dScale ),
								(float) ( are.getHeight( ) * dScale ),
								(float) are.getStartAngle( ),
								(float) are.getAngleExtent( ) );
						pt.lineTo( (float) xc, (float) yc );
						pt.lineTo( (float) xs, (float) ys );
					}
					Region previousClipping = new Region( );
					_gc.getClipping( previousClipping );
					
					_gc.setClipping( pt );
					RectangleRenderEvent rre = (RectangleRenderEvent) ( (EventObjectCache) this ).getEventObject( are.getSource( ),
							RectangleRenderEvent.class );
					rre.setBackground( are.getBackground( ) );
					try