Bug 214453 Some Legend Entries are not correct when the text is shortened by ellipsis
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/LegendBuilder.java
/**
	 * Returns a non empty value, if it is null or empty string, replace with specified value.
	 * 
	 * @param value specified value.
	 * @param defaultValue default return value.
	 * @return a non empty value.
	 */
	private Object getNonEmptyValue( Object value, Object defaultValue )
	{
		if ( value == null || value.toString( ).length( ) == 0 )
		{
			return defaultValue;
		}
		
		return value;
	}
	private double[] computeVerticalByTopBottomValue( IDisplayServer xs,
			Chart cm, SeriesDefinition[] seda, RunTimeContext rtc,
			ITextMetrics itm, Label la, LegendData legendData,
			boolean bNeedInvert)
			throws ChartException
	{
		double dWidth = 0, dHeight = 0;
		double dW, dMaxW = 0, dColumnWidth;
		double dRealHeight = 0, dExtraWidth = 0, dDeltaHeight;
		ArrayList columnList = new ArrayList( );
		
		double dSeparatorThickness = legendData.dSeparatorThickness
				+ legendData.dVerticalSpacing;
		for ( int j = 0; j < seda.length; j++ )