Bug 145274 __isnull does not work properly when parameters have default value
steps to reproduce: - create a report - add a parameter with default value - preview report in web viewer - modify the url with __null pattern expected behavior: - __null takes effect actual behavior: - it simply didn't
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
{
			this.exception = e;
		}
	}
	/**
	 * Init the bean.
	 * 
	 * @param request
	 * @throws Exception
	 */
	protected void __init( HttpServletRequest request ) throws Exception
	{
		if ( ParameterAccessor.isGetImageOperator( request ) )
		{
			return;
		}
		this.category = "BIRT"; 
		this.masterPageContent = ParameterAccessor
				.isMasterPageContent( request );
		this.isDesigner = ParameterAccessor.isDesigner( request );
		this.bookmark = ParameterAccessor.getBookmark( request );
		this.reportPage = String.valueOf( ParameterAccessor.getPage( request ) );
		this.reportDocumentName = ParameterAccessor.getReportDocument( request );
		this.reportDesignName = ParameterAccessor.getReport( request );
		this.format = ParameterAccessor.getFormat( request );
		this.maxRows = ParameterAccessor.getMaxRows( request );
		
		ReportEngineService.getInstance( ).setMaxRows( this.maxRows );
		
		processReport( request );