SpiceDB is an open source database system for creating and managing security-critical application permissions. Prior to version 1.47.1, if a schema includes the following characteristics: permission defined in terms of a union (+) and that union references the same relation on both sides (but one side arrows to a different permission). Then SpiceDB may have missing LookupResources results when checking the permission. This only affects LookupResources; other APIs calculate permissionship correctly. The issue is fixed in version 1.47.1.

Affected: Go: github.com/authzed/spicedb

### Impact

If your schema includes the following characteristics:

1. You have a permission defined in terms of a union (`+`) 1. That union references the same relation on both sides, but one side arrows to a different permission

Then you might have missing `LookupResources` results when checking the permission. This only affects `LookupResources`; other APIs calculate permissionship correctly.

A small concrete example:

``` relation doer_of_things: user | group#member permission do_the_thing = doer_of_things + doer_of_things->admin ```

A CheckPermission on `do_the_thing` will return the correct permissionship, but a LookupResources on `do_the_thing` may miss resources.

#### A Comprehensive Example

If you have a schema with a structure like this:

``` definition special_user {}

definition user { relation special_user_mapping: special_user permission special_user = special_user_mapping } definition group { relation member: user permission membership = member + member->special_user }

definition system { relation viewer: user | group#membership // This is the problematic permission permission view = viewer + viewer->special_user } ```

And these relationships: ``` system:somesystem#viewer@group:somegroup#membership group:somegroup#member@user:someuser1 user:someuser1#special_user_mapping@special_user:specialuser ```

And you call LookupResources with: ``` subject_type: user subject_id: someuser1 permission: view resource_type: system ```

You would expec…