[libvirt] 1.4.0 memballoon bug?

Hi, When I run virsh -c qemu:///system domxml-to-native qemu-argv /tmp/qatest.xml from 1.4.0 with the qatest.xml below (which has no memballoon device specified), I get an 'unspecified error'. Some printf debugging shows that virDomainDefParseXML is automatically adding a virtio memballoon device, but that its memballoon->info.type is 0, not the 1 or 8 which is required at qemuBuildMemballoonDevStr(). This didn't happen at 1.2.0, but I'm not sure where the error was introduced, as I don't see any suspicious changes around any of the relevant functions. So I was hoping to send a patch, but for now I'm just asking for help :) Anyone know what might be going on? thanks, -serge