Bug 211710 [Regression] Data of cascading parameters in the report extended from the library can not be selected from the drop-down list when preview [01]
Description: Data of cascading parameters in the report extended from the library can not be selected from the drop-down list when preview. Build number: 2.2.2.v20071203-0630 Steps to reproduce: 1. New a Library with cascading parameters. 2. New a report and extend the cascading parameters from the library and preview. Expected result: Values can be selected from the drop-down list. Actual result: Values can not be selected from the drop-down list. Error log: N/A
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/GetParameterDefinitionTask.java
ChoiceListCache cache = new ChoiceListCache( parameterHelpers );
			assert( parameterCount > 0 );
			return getSelectionTree( parameters, parameterHelpers, cache,
					new Object[0] );
		}
	}
	private Collection getSelectionTree( SlotHandle parameters,
			ParameterHelper[] parameterHelpers, ChoiceListCache cache,
			Object[] parameterValueAhead )
	{
		int parameterIndex = parameterValueAhead.length;
		int parameterCount = parameters.getCount( );
		ScalarParameterHandle parameter = (ScalarParameterHandle) parameters
				.get( parameterIndex );
		Collection choices = getChoicesFromParameterQuery( parameter );
		Iterator iterator = choices.iterator( );
		Collection result = null;
		while ( iterator.hasNext( ) )
		{
			Object[] values = new Object[parameterIndex + 1];
			for ( int i = 0; i < parameterValueAhead.length; i++ )
			{
				values[i] = parameterValueAhead[i];
			}
			IParameterSelectionChoice choice = (IParameterSelectionChoice) iterator
					.next( );
			Object value = choice.getValue( );
			values[parameterIndex] = value;
			Collection children = null;
			if ( parameterIndex == parameterCount - 1 )