[libvirt] USB device with product id 0x0000

Hi everyone! I'm new to this list and I joined because I stumbled upon a problem I could not find mentioned anywhere. I have a usb device (a bluetooth dongle) that reports a product id of 0x0000. When I try to attach this to a domain I get a "missing product" error. I checked the sources (0.6.3) and found in domain_conf.c lines 1645 following a check for a product id different from 0. If I remove this check and recompile everything works fine. I can attach the device to the virtual machine and it is recognized. I don't know the background of this check and if disabling it has any negative consequences so I would be happy about any comments. Regards André