Bug 139346 Using isTopN in table inside list group header doesn't work.
Description: Using isTopN in table inside list group header doesn't work. Steps to reproduce: 1.Insert a list with a group 2.Insert a table to list group header 3.Using Total.isTopN(row[],2,null,0) as filter expression in table item. 4.Preview Result: Only the first group displayed top 2 records, other groups kept display all records.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
{
						groupName = "_{$TEMP_GROUP_" + i + "$}_";
					}
					IQuery.GroupSpec dest = QueryExecutorUtil.groupDefnToSpec( cx,
							src,
							expr,
							groupName,
							-1 );
					groupSpecs[i] = dest;
					
					temporaryComputedColumns.add( new ComputedColumn( groupName,
						expr,
						QueryExecutorUtil.getTempComputedColumnType( groupSpecs[i].getInterval( ) ) ) );
				}
				odiQuery.setGrouping( Arrays.asList( groupSpecs));
			}		
			
			List sorts = this.baseQueryDefn.getSorts();
			if ( sorts != null && !sorts.isEmpty( ) )
			{
				IQuery.SortSpec[] sortSpecs = new IQuery.SortSpec[ sorts.size() ];
				Iterator it = sorts.iterator();
				for ( int i = 0; it.hasNext(); i++ )
				{
					ISortDefinition src = (ISortDefinition) it.next();
					int sortIndex = -1;
					String sortKey = src.getColumn();
					if( sortKey == null )
						sortKey = src.getExpression().getText();
					else