The Settings page saved whatever was posted, and some lists offered
values the panel cannot use:
- Quota Debug could not be turned off: "False" is a non-empty text and
counted as on.
- VM Clone Name Prefix showed as a True/False list, so no prefix could
be typed, and touching it set the prefix to True.
- Disk SCSI Controller listed " lsilogic" with a space, never shown as
chosen, and virtio-blk, which is no SCSI controller.
- VM Machine Type listed x86_64, an architecture; VM CD-ROM Device
listed virtio, a bus a CD-ROM cannot use.
- Logs per Page and Disk Owner UID/GID are read with int(): a letter
broke the logs page and VM create.
A migration fixes the lists and moves a value they no longer offer to
the default (the clone prefix keeps its text). A listed setting now
takes one of its choices, and every number setting a whole number in
its range, checked before it is saved.