cannot add 2 nodes with same name and different domain

[Alexander Golovchenko]

Hi.
During the deployment, it was noticed that it is impossible to add 2 different servers with the same name, but different domain names to MAAS GUI. I use MAAS 3.0.0
To reproduce the problem add several new servers to the MAAS GUI and try to assign them names node1.domain.com
node1.fqdn.com

[Alexander Golovchenko (avgolovchenko)]

I use
MAAS 3.0.0-10029-g.986ea3e45 on my rack controller and 3.0.0-10029-g.986ea3e45 version from deb packages on region

[Vladimir Grevtsev (vlgrevtsev)]

Quick reproducer:

# check if that's the only machine with the hostname in MAAS
ubuntu@OrangeBox84:~$ maas admin machines read | grep "node07"
        "hostname": "node07",
        "fqdn": "node07.maas",

# expected, since this machine has .maas domain
ubuntu@OrangeBox84:~$ maas admin machine update sgk3gy hostname=node07
{"hostname": ["Node with this Hostname already exists."]}

# creating new domain zone
ubuntu@OrangeBox84:~$ maas admin domains create name=testzone
Success.
Machine-readable output follows:
{
    "authoritative": true,
    "ttl": null,
    "id": 1,
    "is_default": false,
    "resource_record_count": 0,
    "name": "testzone",
    "resource_uri": "/MAAS/api/2.0/domains/1/"
}

# updating machine - moving to new domain zone
ubuntu@OrangeBox84:~$ maas admin machine update sgk3gy domain=testzone
Success.
Machine-readable output follows:
<omitted>

# expected: Success
# actual result: machine cannot be assigned with fqdn node07.testzone
ubuntu@OrangeBox84:~$ maas admin machine update sgk3gy hostname=node07
{"hostname": ["Node with this Hostname already exists."]}

For the record, UI doesn't show anything (even any error) as well.