Bug 122854 There is redundant columns in "available columns" list in "export data" dialog.
Description: There is redundant columns in "available columns" list in "export data" dialog. Steps to reproduce: 1. Preview attached design in web viewer. 2. Select the table and click on "export" button. 3. There is a "detail" column name in "available columns" list which is not data set column.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/ReportQueryBuilder.java
for ( int i = 0; i < list.getGroupCount( ); i++ )
				{
					handleListGroup( list.getGroup( i ),
							(GroupHandle) groupsSlot.get( i ), value );
				}
				if ( list.getDetail( ).getContentCount( ) != 0 )
				{
					query.setUsesDetails( true );
				}
				pushExpressions( query.getRowExpressions( ) );
				visitListBand( list.getDetail( ), value );
				popExpressions( );
				pushExpressions( query.getAfterExpressions( ) );
				visitListBand( list.getFooter( ), value );
				popExpressions( );
			}
			finishVisit( query );
			registerQueryAndElement( query, list );
			return value;
		}
		/*
		 * (non-Javadoc)
		 * 
		 * @see org.eclipse.birt.report.engine.ir.ReportItemVisitor#visitTextItem(org.eclipse.birt.report.engine.ir.TextItemDesign)
		 */
		public Object visitTextItem( TextItemDesign text, Object value )
		{
			BaseQueryDefinition query = prepareVisit( text );
			handleReportItemExpressions( text );
			HashMap exprs = text.getExpressions( );