Bug 162841 [regression]Drill-through link to document containing parameters failed in html and pdf
Description: Drill-through link to document containing parameters failed in html and pdf Steps to reproduce: 1. New a report with a report parameter, don't set default value for it. 2. Preview in Web Viewer, input parameter value and save the report document to c:\ 3. New another report, insert a label, set a drill through link on the label, link to the report document. 4. Preview in web viewer, html and pdf, click the link. Expected result: Link to target report. Actual result: In html, a dialog popped up and said "a runtime error has occurred" In pdf, a dialog popped up and said that report parameter has null value. In frameset servlet, both formats are ok. I found that if I set default value for the report parameter in target report, the issue will disappear.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
while ( configVars != null && configVars.hasNext( ) )
				{
					ConfigVariableHandle configVar = (ConfigVariableHandle) configVars
							.next( );
					if ( configVar != null && configVar.getName( ) != null )
					{
						String paramName = configVar.getName( );
						Object paramValue = configVar.getValue( );
						
						if ( paramName.toLowerCase( ).startsWith(
								ParameterAccessor.PARAM_ISNULL )
								&& paramValue != null )
						{
							String nullParamName = getParameterName( (String) paramValue );
							if ( nullParamName != null )
								this.configMap.put( nullParamName, null );
							continue;
						}
						
						else if ( ( displayTextParam = ParameterAccessor
								.isDisplayText( paramName ) ) != null )
						{
							paramName = getParameterName( displayTextParam );
							if ( paramName != null )
							{
								if ( this.displayTexts == null )
									this.displayTexts = new HashMap( );
								this.displayTexts.put( paramName, paramValue );
							}
							continue;