Bug 195607 NPE is thrown when calling DimensionHandle:: getAbsoluteValue()
If a DimensionHandle did not set DimensionValue, NPE will thrown when calling DimensionHandle:: getAbsoluteValue().
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/CSSLengthValueHandler.java
{
	final static String ABSOLUTE_FONT_SIZE_CONSTANTS[] = {
			DesignChoiceConstants.FONT_SIZE_XX_SMALL,
			DesignChoiceConstants.FONT_SIZE_X_SMALL,
			DesignChoiceConstants.FONT_SIZE_SMALL,
			DesignChoiceConstants.FONT_SIZE_MEDIUM,
			DesignChoiceConstants.FONT_SIZE_LARGE,
			DesignChoiceConstants.FONT_SIZE_X_LARGE,
			DesignChoiceConstants.FONT_SIZE_XX_LARGE};
	static DimensionValue defaultFontSizeValue = null;
	IAbsoluteFontSizeValueProvider provider;
	DimensionHandle dimensionHandle;
	CSSLengthValueHandler( DimensionHandle dimensionHandle )
	{
		this.dimensionHandle = dimensionHandle;
		DesignSession session = dimensionHandle.getElementHandle( ).getModule( )
				.getSession( );
		provider = session.getPredefinedFontSizeProvider( );
	}
	/**
	 * Returns the default value of the property this handler is processing on.
	 * 
	 * @return the default value in dimension value
	 */
	DimensionValue getDefaultFontSizeValue( )
	{