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
{
			e.printStackTrace( );
		}
		
		ScalarParameterHandle parameter = (ScalarParameterHandle) findParameter( paramName );
		
		if ( defaultValueObj != null && parameter != null )
		{
			String dataType = parameter.getDataType( );
			String pattern = parameter.getPattern( );
			if ( DesignChoiceConstants.PARAM_TYPE_DATETIME
					.equalsIgnoreCase( dataType ) )
			{
				
				return defaultValueObj;
			}
			if ( DesignChoiceConstants.PARAM_TYPE_STRING
					.equalsIgnoreCase( dataType ) )
			{
				pattern = null;
			}
			defalutValue = ParameterValidationUtil.getDisplayValue( null,
					pattern, defaultValueObj, locale );
		}
		
		if ( defalutValue == null && parameter != null )
		{
			defalutValue = parameter.getDefaultValue( );
		}
		return defalutValue;