InternalizeRefs can result in a stack overflow with recursive references

[jamietanna]

When trying to InternalizeRefs on a recursive reference, we get a Stack Overflow error.

Spec (via)

openapi: 3.0.2
info:
  version: '0.0.1'
  title: example
  description: |
    Make sure that recursive types are handled properly
paths:
  /example:
    get:
      operationId: exampleGet
      responses:
        '200':
          description: "OK"
          content:
            'application/json':
              schema:
                $ref: '#/components/schemas/Document'
components:
  schemas:
    Document:
      type: object
      properties:
        fields:
          type: object
          additionalProperties:
            $ref: '#/components/schemas/Value'
    Value:
      type: object
      properties:
        stringValue:
          type: string
        arrayValue:
          $ref: '#/components/schemas/ArrayValue'
    ArrayValue:
      type: array
      items:
        $ref: '#/components/schemas/Value'

Not sure if this is allowed behaviour in OpenAPI, but it's something we test against in our project, and may be worth us protecting against here, too?

[jamietanna]

Looks like this has been resolved in a later release, quite possibly due to changes in #628 🚀