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
}
	public List getErrors( )
	{
		return executionContext.getErrors( );
	}
	public IReportContext getReportContext( )
	{
		return executionContext.getReportContext( );
	}
	private void mergeOption( IRenderOption options, String name, Object value )
	{
		if ( options != null )
		{
			if ( value != null && !options.hasOption( name ) )
			{
				options.setOption( name, value );
			}
		}
	}
	/**
	 * intialize the render options used to render the report.
	 * 
	 * the render options are load from:
	 * <li> engine level default options</li>
	 * <li> engine level format options</li>
	 * <li> engine level emitter options</li>
	 * <li> task level options </li>
	 * 
	 */
	protected void setupRenderOption( )