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/image/JavaxImageIOWriter.java
* @see org.eclipse.birt.chart.device.IDeviceRenderer#before()
	 */
	public void before( ) throws ChartException
	{
		super.before( );
		_bImageExternallySpecified = ( _img != null );
		
		
		if ( !_bImageExternallySpecified )
		{
			if ( _bo == null ) 
			
			{
				throw new ChartException( ChartDeviceExtensionPlugin.ID,
						ChartException.RENDERING,
						"JavaxImageIOWriter.exception.no.bounds", 
						Messages.getResourceBundle( getULocale( ) ) );
			}
			if ( (int) _bo.getWidth( ) <= 0 || (int) _bo.getHeight( ) <= 0 )
			{
				throw new ChartException( ChartDeviceExtensionPlugin.ID,
						ChartException.INVALID_IMAGE_SIZE,
						"JavaxImageIOWriter.exception.invalid.image.size", 
						Messages.getResourceBundle( getULocale( ) ) );
			}
			
			_img = new BufferedImage( (int) _bo.getWidth( ),
					(int) _bo.getHeight( ),
					getImageType( ) );
		}