Bug 167511 [Block]NPE when using customized IStyleProcessor with Chart Generator and no Chart will be rendered
Use a customized IStyleProcessor with Generator.build() and the chart will not be rendered in UI.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/factory/Generator.java
else if ( component instanceof Text )
		{
			IStyle style = getMingledStyle( model, type, externalProcessor );
			Text text = (Text) component;
			if ( text.getFont( ) == null )
			{
				text.setFont( style.getFont( ) );
			}
			else
			{
				FontDefinition newFont = style.getFont( );
				FontDefinition font = text.getFont( );
				ChartUtil.mergeFont( font, newFont );
			}
			if ( text.getColor( ) == null )
			{
				text.setColor( style.getColor( ) );
			}
		}
	}
	private IStyle getMingledStyle( Chart model, StyledComponent type,
			IStyleProcessor externalProcessor )
	{
		SimpleContainer rStyle = new SimpleContainer( );
		if ( externalProcessor != null )
		{
			while ( !updateHierarchyStyle( model,
					type,
					externalProcessor,
					rStyle )