Description of problem:

GET request on /api/fact_values and /api/hosts/:host_id/facts shows no results if using per_page=all but works fine if we use a positive integer i.e. per_page=10 or per_page=9999

They perhaps are part of the same underlying code as I can see both of them from https://satellite.example.com/apidoc/v2/fact_values/index.html

This problem is not present in the /api/hosts endpoint though.

GET on /api/v2/hosts/?per_page=all and /api/v2/hosts/?per_page=10 will print exact same set of result if you have 10 systems .

Version-Release number of selected component (if applicable):

Satellite 6.10 (all earlier versions of satellite)

How reproducible:

Always

Steps to Reproduce:
1. Install and configure a Satellite 6.10 and register a system with the same.

2. Run the following APIs against the ID of the registered system e.g. here it is 117

1. curl -ku admin:password https://`hostname -f`/api/v2/hosts/117/facts?per_page=all

1. curl -ku admin:password https://`hostname -f`/api/v2/hosts/117/facts?per_page=5

Actual results:

1. curl -ku admin:RedHat1! https://`hostname -f`/api/v2/hosts/117/facts?per_page=all
   {
   "total": 331,
   "subtotal": 0,
   "page": 1,
   "per_page": 331,
   "search": " host = 117",
   "sort": { "by": null, "order": null }

   ,
   "results": {}
   }

1. curl -ku admin:RedHat1! https://`hostname -f`/api/v2/hosts/117/facts?per_page=5
   {
   "total": 331,
   "subtotal": 1,
   "page": 1,
   "per_page": 5,
   "search": " host = 117",
   "sort": { "by": null, "order": null }

   ,
   "results": {"rhel7.example.com":{"ansible_device_links::ids":null,"ansible_device_links::uuids":null,"ansible_device_links::masters":null,"ansible_device_links":null,"ansible_default_ipv4":null}}
   }

Expected results:

The per_page=all should be able to list all the fact_names and values related to that host.

Additional info:

There's a Redmine present already i.e. https://projects.theforeman.org/issues/31897