The property is parsed using virTristateBoolTypeFromString() but
formatted as if it was a regular bool, which results in the
following incorrect conversion:
BOOL_ABSENT -> managed='no'
BOOL_YES -> managed='yes'
BOOL_NO -> managed='yes'
Use the virTristateBoolTypeToString() helper to ensure the
setting can survive a roundtrip conversion.
Fixes: 4b4a981d60
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>