Bug 141255 No error for the incompatible parameter value
Steps to reproduce: 1.New a decimal parameter, set the default value to "aaa" 2.Preview the report by "Preview" tab Expected result: Error to say the incompatible parameter value Actual result: Parameter request page keeps poping up till input the decimal value Note: if preview in Web Viewer, error will be thrown out, but no exception description.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/parameter/ComboBoxParameterFragment.java
import org.eclipse.birt.report.utility.ParameterAccessor;
/**
 * Fragment help rendering scalar parameter.
 * <p>
 * 
 * @see org.eclipse.birt.report.presentation.aggregation.BaseFragment
 */
public class ComboBoxParameterFragment extends ScalarParameterFragment
{
	/**
	 * Protected constructor.
	 * 
	 * @param parameter
	 *            parameter definition reference.
	 */
	public ComboBoxParameterFragment( ParameterDefinition parameter )
	{
		super( parameter );
	}
	protected void prepareParameterBean( HttpServletRequest request,
			IViewerReportService service, ScalarParameterBean parameterBean,
			Locale locale ) throws ReportServiceException
	{
 		ViewerAttributeBean attrBean = ( ViewerAttributeBean ) request
 				.getAttribute( "attributeBean" ); 
 		assert attrBean != null;
 		
		InputOptions options = new InputOptions( );
		options.setOption( InputOptions.OPT_REQUEST, request );
		Collection selectionList = null;