Inconsistent behaviour in openstack backup restore BACKUP_ID VOLUME_ID

[Arnaud Garin]

On openstack documentation page `Back up and restore volumes and snapshots` the command to restore a backup is presented as follows `openstack volume backup restore BACKUP_ID VOLUME_ID`

However in the CLI the VOLUME_ID is not specified as a mandatory parameter

`openstack volume backup restore [-h] [-f {json,shell,table,value,yaml}] [-c COLUMN] [--noindent] [--prefix PREFIX] [--max-width <integer>] [--fit-width] [--print-empty] [--force] <backup> [<volume>]`

Then when I try to restore a backup with `openstack volume backup restore <backup-id>` I get hit with an error `Either of 'name' or 'volume_id' must be specified.`. Which is still somehow logical.

However when I try to restore a backup with 2 arguments `openstack volume backup restore <backup-id> 12345` I get hit with another error `too many values to unpack (expected 2)`.

What is even funnier is that in the second case the restore still goes through !

```
+--------------------------------------+-----------+-----------+------+-------------------------------+
| ID | Name | Status | Size | Attached to |
+--------------------------------------+-----------+-----------+------+-------------------------------+
| <Other ID> | 12345 | available | 1 | |
| <ID> | | in-use | 1 | Attached to NAME on /dev/vda |
+--------------------------------------+-----------+-----------+------+-------------------------------+
```

Any opinions on that ?

I use a custom made cinder backup driver if that is any relevant.

EDIT: Additional config information

root@stackdev:/opt/stack/devstack# sudo -u stack git describe --all --long
heads/master-0-g1ba76adc

root@stackdev:/opt/stack/devstack# cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.3 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.3 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy