Bug 194785 Stacked bars are drawn incompletely when window is minimed
If I have a stacked bar chart, and i minimize window or bring another window in front so that the view is blocked by the new window, when the window is minimized, all the drawing in the charts is erased, and the view has to be closed and re-opened before the charts appear correctly again. I think this problem is because of the fix for 182279. I will attach the sample test case
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/AxisSubUnit.java
}
	public final void reset( )
	{
		dValueLastNegative = 0;
		dValueLast = 0;
	}
	
	/**
	 * Returns if current positive and negative values are aggregated together
	 * or not
	 * 
	 * @return true: together, false: by sign respectively
	 */
	public boolean isStackTogether( )
	{
		return bStackTogether;
	}
	
	/**
	 * Accumulates the value and returns the result.
	 * 
	 * @param dValue
	 *            the value to accumulate
	 * @return the result value after accumulating
	 * @see #isStackTogether()
	 * @see #getStackedValue(double)
	 */
	public final double stackValue( double dValue )
	{
		if ( bStackTogether )