Hosted: POST and PUT /groups accept users, clients or groups but do nothing with them

POST /groups accepts "users", "clients" and "groups" as input (does not throw a 400), but does not populate them. PUT /groups/x does the same, even returning them from the request. This appears to be at least a partial cause of https://github.com/chef/cheffish/issues/90 .

When I have an org named essentials and a file x.json:

{
  "users": [
    "jkeiser"
  ],
  "clients": [
    "essentials-validator"
  ],
  "groups": [
    "admins"
  ],
  "orgname": "essentials",
  "name": "x",
  "groupname": "x"
}

I see the following:

jkeiser@Ettores-MacBook-Pro-2 ~/e/essentials> knife raw -m POST /groups -i x.json
{
  "uri": "https://api.opscode.com/organizations/essentials/groups/x"
}
jkeiser@Ettores-MacBook-Pro-2 ~/e/essentials> knife raw /groups/x
{
  "actors": [
  ],
  "users": [
  ],
  "clients": [
  ],
  "groups": [
  ],
  "orgname": "essentials",
  "name": "x",
  "groupname": "x"
}

If I follow it up with a PUT from the same file, I get:

jkeiser@Ettores-MacBook-Pro-2 ~/e/essentials> knife raw -m PUT /groups/x -i x.json
{
  "users": [
    "jkeiser"
  ],
  "clients": [
    "essentials-validator"
  ],
  "groups": [
    "admins"
  ],
  "orgname": "essentials",
  "name": "x",
  "groupname": "x"
}
jkeiser@Ettores-MacBook-Pro-2 ~/e/essentials> knife raw /groups/x
{
  "actors": [
  ],
  "users": [
  ],
  "clients": [
  ],
  "groups": [
  ],
  "orgname": "essentials",
  "name": "x",
  "groupname": "x"
}

Start by locating the hosted API handlers for POST /groups and PUT /groups/:name, then reproduce the issue with the provided knife raw requests and x.json payload. Trace how users, clients, and groups are handled and verify that a follow-up GET returns the submitted actors when the fix is complete.