Bug 140395 IImage.getID() return null on chart images
When I use image.getID() to retrieve ID of chart image, it always returns null.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/Image.java
}
				return null;
			case IImage.CUSTOM_IMAGE :
				return new ByteArrayInputStream( this.data );
			case IImage.DESIGN_IMAGE :
				return new ByteArrayInputStream( this.data );
			case IImage.URL_IMAGE :
				try
				{
					URL url = new URL( this.id );
					return new BufferedInputStream( url.openStream( ) );
				}
				catch ( MalformedURLException e )
				{
				}
				catch ( IOException e1 )
				{
				}
				return null;
			case IImage.INVALID_IMAGE :
				return null;
			default :
				return null;
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.engine.api2.IImage#writeImage(java.io.File)
	 */