Requests for non-existent entries return 200 OK and a partially empty JSON result

[johnsca]

$ curl http://interfaces.juju.solutions/api/v1/layer/dummy/ -i
HTTP/1.1 200 OK
Content-Length: 97
Server: TornadoServer/4.2.1
Content-Type: application/json
Etag: "83859d0b8e12f199785658abfb194c24d132f4e1"
Date: Thu, 03 Dec 2015 19:20:35 GMT

{
  "id": "dummy",
  "version": 1,
  "summary": "",
  "repo": "",
  "name": "",
  "owner": null
}

This is causing juju/charm-tools/issues/56 due to build/fetchers.py#L62. I'm going to add a work-around in juju/charm-tools by checking for a value in repo but this should be addressed here as well.

[johnsca]

I missed that there was already a check for repo in the results, but it isn't correct. I still think that the registry should not return a 200 OK result for missing entries.