Bug 156084 __bookmark doesn't work in pdf with frameset servlet
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ViewerHTMLActionHandler.java
String baseURL = null;
		Object renderContext = getRenderContext( context );
		if ( renderContext instanceof HTMLRenderContext )
		{
			baseURL = ( (HTMLRenderContext) renderContext ).getBaseURL( );
		}
		if ( renderContext instanceof PDFRenderContext )
		{
			baseURL = ( (PDFRenderContext) renderContext ).getBaseURL( );
		}
		if ( baseURL == null )
			baseURL = IBirtConstants.VIEWER_RUN;
		StringBuffer link = new StringBuffer( );
		String reportName = getReportName( context, action );
		if ( reportName != null && !reportName.equals( "" ) ) 
		{
			link.append( baseURL );
			link
					.append( reportName.toLowerCase( )
							.endsWith( ".rptdocument" ) ? "?__document=" : "?__report=" ); 
			try
			{
				link.append( URLEncoder.encode( reportName,
						ParameterAccessor.UTF_8_ENCODE ) );
			}
			catch ( UnsupportedEncodingException e1 )
			{
				
			}