Bug 135207 parameter dialog is not displayed when drill through to a PDF report that contains parameter with no default value
steps to reproduce: - create 1st report - add a report parameter (no default value) - create 2nd report - add a label "link" - edit hyperlink property (type: drill-through, target report format: PDF) - preview 1st report - click on "link" expected behavior: - parameter dialog should be displayed - target report is rendered in PDF format actual behavior: - "Some required parameter values are not set or set to incompatible data type." was displayed instead.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/layout/EngineFragment.java
* Render the report in html/pdf format by calling engine service.
	 * 
	 * @param request
	 *            incoming http request
	 * @param response
	 *            http response
	 * @exception ServletException
	 * @exception IOException
	 */
	protected void doService( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException, IOException
	{
		ViewerAttributeBean attrBean = ( ViewerAttributeBean ) request
				.getAttribute( "attributeBean" ); 
		assert attrBean != null;
		ServletOutputStream out = response.getOutputStream( );
		GetUpdatedObjectsResponse upResponse = new GetUpdatedObjectsResponse( );
		IContext context = new BirtContext( request, response );
		Operation op = null;
		try
		{
			if ( "/download".equalsIgnoreCase( request.getServletPath( ) ) ) 
			{
				BirtExtractDataActionHandler extractDataHandler = new BirtExtractDataActionHandler(
						context, op, upResponse );
				extractDataHandler.execute( );
			} else if ( ParameterAccessor.isGetImageOperator( request ) )
			{
				BirtRenderImageActionHandler renderImageHandler = new BirtRenderImageActionHandler(
						context, op, upResponse );