A host owner can either be a user or a usergroup, this is implemented in the database with two columns.

MariaDB [foreman]> desc hosts;
+----------------------+--------------+------+-----+---------+----------------+
| Field                | Type         | Null | Key | Default | Extra          |
+----------------------+--------------+------+-----+---------+----------------+
...
| owner_id             | int(11)      | YES  |     | NULL    |                |
| owner_type           | varchar(255) | YES  |     | NULL    |                |
...
+----------------------+--------------+------+-----+---------+----------------+

The owner_type checking seems to be inconsistent in the ruby code (not everywhere implemented where needed). I found one case where I can produce an obvious error, while tracking this error through the code I found some other possible errors.

obvious error

steps to reproduce:

• need to have organizations enabled
• create a sampe organization
• create a user with a specific user id (eg. 25)
• create a group with the same id
• set the group as owner for a host
• set the sample organzation for the host

found error:

• navigate to Administer->Users
• open the user
• open the Organizations part
• the user has the organization assigned and is is grey (Message: "this is used by a host")

I know the code error should be in app/models/concerns/taxonomix.rb:get_taxonomy_ids, but my understanding of ruby is to limited to code a solution for this. :(

possible errors
in app/models/user.rb:

has_many :direct_hosts,      :class_name => 'Host',    :as => :owner

I think this is missing the where condition to check for the correct type.

This should be:

has_many :direct_hosts,      -> { where(:owner_type => 'User') }, :class_name => 'Host',    :as => :owner

in app/models/usergroup.rb

has_many_hosts :as => :owner

Same as above.

I can generate a pull request for the simple things, but I need help to create a correct patch for taxonomix.rb