Duplicate device name, different site triggers uniqueness error

[DanSheps]

Environment

• Python version: 3.6
• NetBox version: 2.7.10

Steps to Reproduce

1. Create two sites S1 & S2
2. Create a device, D1 in site S1
3. Create a device D1 in site S2

Expected Behavior

Create D1 in S2 successfully

Observed Behavior

Validation Error: "A device with this name already exists"

Reason

In validate_unique() on the device model, we are suppose to be looking for a device assigned to the same site with no tenant. However, we are not setting the site and instead only looking for a duplicate name.

Fix

1393 -            if Device.objects.exclude(pk=self.pk).filter(name=self.name, tenant__isnull=True):
1393 +            if Device.objects.exclude(pk=self.pk).filter(name=self.name, site=self.site, tenant__isnull=True):