Bug 148626 [Regression]Can't fetch value from the filter of table/chart which inherites data from container
Steps: 1. create a table and bind a dataset in it 2. create another table/chart in the table detail/table group header 3. switch to the Filter tab in property editor 4. create a filter and select value in "<select value...>" combo 5. an error popuped up, "The expression value can't be retrieved"
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/ReportDataServiceProvider.java
public int invoke( int command )
	{
		if ( command == COMMAND_NEW_DATASET )
		{
			return invokeNewDataSet( );
		}
		else if ( command == COMMAND_EDIT_FILTER )
		{
			return invokeEditFilter( );
		}
		else if ( command == COMMAND_EDIT_PARAMETER )
		{
			return invokeEditParameter( );
		}
		else if ( command == COMMAND_EDIT_BINDING )
		{
			return invokeDataBinding( );
		}
		return Window.CANCEL;
	}
	protected int invokeNewDataSet( )
	{
		List dataSources = getReportDesignHandle( ).getVisibleDataSources( );
		if ( dataSources.isEmpty( ) )
		{
			
			new NewDataSourceAction( ).run( );
		}
		IAction action = new NewDataSetAction( );
		PlatformUI.getWorkbench( ).getHelpSystem( ).setHelp( action,