Domains: it's possible to add different types of DNS records with the same label

[klimeryk]

As reported by @umurkontaci in #2262 (comment), it's possible to add different types of DNS records (say an A and CNAME records) pointing to the same label (test.example.com).

[designsimply]

Tested and confirmed with the following steps to reproduce:

1. Go to Domains > %domainname% > Name Servers and DNS
2. Click the Add New DNS Record button
3. Enter an A record with the subdomain "test"
4. Enter a CNAME record with the subdomain "test"

Result: I was able to set A record and CNAME recording to the same point. I shouldn't be able to do that.

^{Seen at https://wordpress.com/domains/manage/threedotonefour.com/dns/design5279.wordpress.com using Chrome 50.0.2661.94 on Mac OS X 10.11.4}

Also noting that this issue is 97 days old with no activity. @klimeryk, can this issue be moved to a milestone where it will be reviewed in a reasonable time? If not, I recommend closing it as wontfix.

[klimeryk]

We don't have a milestone for such issues, but this is also being tracked on our Trello board and it will surely be fixed (sooner or later :/). Would assigning it to a milestone (something like Cobalt: Backlog) help you during bug scrubs and such to filter out issues that really deserve some love?

[umurkontaci]

I would rather not close these types of issues; they are not exactly a priority today, but I want to fix them when we can focus on the DNS editor.

[umurkontaci]

For the record, I think we should only prevent a record to coexist with a CNAME record under the same name.

We can't have CNAME and A records at the same name, but we can certainly have A, AAAA, MX, TXT records under the same name and it wouldn't be a problem.

[rachelmcr]

I tested and confirmed that this issue is still valid, using the steps @designsimply provided above.

[klimeryk]

This has been fixed on the backend when we added additional validation to make sure the new DNS zone would remain valid.

It's not the prettiest, but it's quite robust and comprehensive.