The custom create form shows a MAC per network (random, or typed in),
but had no mac field: the script wrote the joined list into every
name="mac" input of the page, the other six-plus forms' own MAC fields,
so a flavor form then sent one MAC per custom network and was refused,
and the custom VM got other MACs from libvirt. The custom form gets its
own hidden mac field and the script writes only there. The field took
17 characters, one MAC, so the API also refused a VM with two NICs and
their MACs; it takes 255. The serializer's test sent no submission_key,
so its check for more MACs than networks never ran; it does now, next
to the case of two networks with two MACs.
Changing a disk's device type in the custom create form asked for its
buses at /archs/undefined/machines/undefined/...: the script read the
architecture and machine from a select[name=arch] and #machine-control
the page does not have. The request failed (500) and the bus list kept
the disk's buses, so a CD-ROM could be put on virtio. The script takes
both from the page's own URL.
