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
IQueryResults actualResultSet = session.executeQuery( queryDefn,
					itemHandle.getPropertyHandle( ReportItemHandle.PARAM_BINDINGS_PROP )
							.iterator( ),
					itemHandle.getPropertyHandle( ExtendedItemHandle.FILTER_PROP )
							.iterator( ),
					getColumnDataBindings( itemHandle ) );
			if ( actualResultSet != null )
			{
				String[] expressions = columnExpression;
				int columnCount = expressions.length;
				IResultIterator iter = actualResultSet.getResultIterator( );
				while ( iter.next( ) )
				{
					if ( isStringType )
					{
						String[] record = new String[columnCount];
						for ( int n = 0; n < columnCount; n++ )
						{
							record[n] = iter.getString( expressions[n] );
						}
						dataList.add( record );
					}
					else
					{
						Object[] record = new Object[columnCount];
						for ( int n = 0; n < columnCount; n++ )
						{
							record[n] = iter.getValue( expressions[n] );
						}
						dataList.add( record );