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
catch ( Exception ex )
			{
			}
			if ( runningStatus != STATUS_RUNNING )
			{
				return;
			}
		} while ( waitingTime < 5000 );
		return;
	}
	public boolean getCancelFlag( )
	{
		return cancelFlag;
	}
	public void setErrorHandlingOption( int option )
	{
		if ( option == CANCEL_ON_ERROR )
		{
			executionContext.setCancelOnError( true );
		}
		else
		{
			executionContext.setCancelOnError( false );
		}
	}
	/**
	 * class used to visit all parameters
	 * 
	 */
	static abstract class ParameterVisitor