Bug 202236 When select NULL value for multi-value parameter, cause NPE.
Description: When select NULL value for multi-value parameter, cause NPE. Build number: 2.2.1 Steps to reproduce: 1, New a list parameter, check Allow multi-value, uncheck isRequired 2, Select parameter data type as Date 3, Add some items into list 4, Preview 5, Select Null Value item in list Expected result: Can accept Null value for multi-value parameter Actual result: Cause NPE.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineTask.java
}
				}
				else if ( param instanceof ScalarParameterHandle )
				{
					if ( !visitScalarParameter( (ScalarParameterHandle) param,
							value ) )
					{
						return false;
					}
				}
			}
			return true;
		}
		boolean visitCascadingParamterGroup(
				CascadingParameterGroupHandle group, Object value )
		{
			return visitParameterGroup( group, value );
		}
		boolean visitParameterGroup( ParameterGroupHandle group, Object value )
		{
			return false;
		}
		boolean visitScalarParameter( ScalarParameterHandle param, Object value )
		{
			return false;
		}
		boolean visit( ReportDesignHandle report )
		{
			return visit( report, null );
		}