Bug 190984 xtab filter/sort did not work properly when using a joined data set
steps to reproduce: - use the attached report - try to add a filter/sort on xtab, e.g. using country column - notice that the value list is unavailable - try to enter the filter/sort condition manually, e.g. "USA" - preview in layout expected behavior: - when use joined data set, the value list should be available - report should be previewed properly actual behavior: - the value list was unavailable - NPE was thrown out when preview the report with the filter/sort condition being completed manually
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/CubeQueryUtil.java
* 
	 * @param expr
	 * @return
	 */
	private String getReferencedMeasureName( IBaseExpression expr )
	{
		return OlapExpressionCompiler.getReferencedScriptObject( expr, "measure" );
	}
	
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.report.data.adapter.api.ICubeQueryUtil#getMemberValueIterator(org.eclipse.birt.report.model.api.olap.TabularCubeHandle, java.lang.String, org.eclipse.birt.data.engine.olap.api.query.ICubeQueryDefinition)
	 */
	public Iterator getMemberValueIterator( TabularCubeHandle cubeHandle,
			String dataBindingExpr, ICubeQueryDefinition queryDefn )
			throws AdapterException
	{
		try
		{
			if ( cubeHandle == null
					|| dataBindingExpr == null || queryDefn == null )
				return null;
			Set dimLevels = OlapExpressionCompiler.getReferencedDimLevel( new ScriptExpression( dataBindingExpr ),
					queryDefn.getBindings( ),
					true );
			if ( dimLevels.size( ) == 0 || dimLevels.size( ) > 1 )
				return null;
			DimLevel target = (DimLevel) dimLevels.iterator( ).next( );
			TabularHierarchyHandle hierHandle = (TabularHierarchyHandle) ( cubeHandle.getDimension( target.getDimensionName( ) ).getContent( TabularDimensionHandle.HIERARCHIES_PROP,
					0 ) );