[Koha] Checking out with no barcode opens a print dialog

Gentle Reader, We have noticed a strange behaviour in Koha 17.05 and 17.11 when checking books out. If you select a patron, then click "Check out" without entering an item barcode, a new window opens with a printer dialog to print a list of the books checked out. Is this considered a feature or a bug? It certainly took us by surprise! Best Regards, Chris Brown