Sorry for the long summary, but it kind of says it all.
If using the marcHoldings feature of Net::Z3950::FOLIO with the restrictToItem option, a record returned from a barcode search will generate a MARC field for a holdings record even though there is no match to the item barcode, if there are no item records attached to the holdings record.
To reproduce, use the attached config.able2.json (contact Wayne Schneider for credentials if needed) with the Z39.50 search f @1=9998 115165670. The record returned will contain 2 952 fields, one with the item that was searched for, and one for a holdings record that has no items.
Reproduced with v2.4.0 and with HEAD of master.