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
{
	/**
	 * Anything before do service.
	 * 
	 * @param request
	 *            incoming http request
	 * @param response
	 *            http response
	 * @exception ServletException
	 * @exception IOException
	 */
	protected void doPreService( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException, IOException
	{
		if ( "/download".equalsIgnoreCase( request.getServletPath( ) ) ) 
		{
			response.setContentType( "application/csv;charset=utf-8" ); 
			response.setHeader(
					"Content-Disposition", "inline; filename=exportdata.csv" ); 
		} else if ( ParameterAccessor.PARAM_FORMAT_PDF
				.equalsIgnoreCase( ParameterAccessor.getFormat( request ) ) )
		{
			response.setContentType( "application/pdf" ); 
		} else
		{
			response.setContentType( "text/html;charset=utf-8" ); 
			response.setHeader( "cache-control", "no-cache" ); 
		}
	}
	/**