Loading openapi schema with loop references ends-up with endless loop and crashing with "stack overflow" error

[panush]

I'm using kin-openapi v0.89.0.
when trying to load the below openapi (with a reference loop in it), kin-openapi is crashing after getting into an endless loop (see attached file)
kin-openapi-endless-loop-error.txt

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets:
    patch:
      requestBody:
        content:
          application/json:
            schema:
              oneOf:
                - $ref: '#/components/schemas/Cat'
                - $ref: '#/components/schemas/Kitten'
              discriminator:
                propertyName: pet_type
      responses:
        '200':
          description: Updated
components:
  schemas:
    Cat:
      anyOf: 
        - $ref: '#/components/schemas/Kitten'
        - type: object
          properties:
            hunts:
              type: boolean
            age:
              type: integer
            offspring:
    Kitten: 
      $ref: '#/components/schemas/Cat'

[fenollp]

Hi @panush please use backticks to share your YAML. See https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#quoting-code

Am I correct in assuming that components' Cat's offspring field is empty?

[fenollp]

I investigated a bit but ran out of time. FYI this can be used as a temporary work around:

components:
  schemas:
    Kitten:
      $ref: '#/components/schemas/Cat' # before
      allOf:                           # after
        $ref: '#/components/schemas/Cat'

I'd appreciate help on this issue. I don't have much available time these days.

[TristanSpeakEasy]

@panush do the recent PR that was merged sort your issue here?

[maciej]

It seems to be fixed, see https://go.dev/play/p/cC6HQ4xXC_M.

Returns with:

err: invalid schema: value MUST be an object

@fenollp perhaps you can close the issue?