Schema reference not parsed as expected, results in circular reference

[ShaunLoganOracle]

It looks like there is an issue parsing schema references of a certain structure in an OA3 json document. The problem manifests when schema A is defined (only) as ""$ref":"#/components/schemas/B". in this case, the OpenApiDocument.Components.Schemas entry for A, has an UnresolvedReference, but the Reference.Id is #/components/schemas/A.

To demonstrate this using PetStore (OA 3, json), I have made two changes:

1. change the response for the /pets path's Get operation to refer to AllPets:
   it was:
   "$ref": "#/components/schemas/Pets"
   change to:
   "$ref": "#/components/schemas/AllPets"
   and then,
2. add the new AllPets schema definition:
   "AllPets": { "$ref":"#/components/schemas/Pets" },
   (yes, this seems unnecessary, but in my case I don't control the OA3 json generation, I'm just trying to parse it).

Per my reading of the OA3 spec, this syntax/structure should be valid: the schemas element is a map of string (schema id) to either a schema or a reference object.
From: OA3 spec.

When I attempt to ResolveSchema() on the AllPets schema object, it fails to resolve - I would expect it to resolve to the Pets schema object:
` string oaFilepath = GetTestFilepath ("petstore-3.0.json");

 OpenApiStreamReader reader = new OpenApiStreamReader ();
 using (Stream file = new FileStream (oaFilepath, FileMode.Open))
 {
    OpenApiDocument doc = reader.Read (file, out OpenApiDiagnostic diags);
    OpenApiSchema schema1 = doc.Components.Schemas["AllPets"];
    if (!schema1.UnresolvedReference)
       return;
    OpenApiSchema schema2 = (OpenApiSchema)doc.ResolveReference (schema1.Reference);
    if (schema2.UnresolvedReference && schema1.Reference.Id == schema2.Reference.Id)
    {
       // detected a cycle - this code gets triggered
       Log ("This is a circular reference, WTF? {0}", schema1.Reference.Id);
    }
 }

`
I am fairly new to using OpenApi.NET so I might be misunderstanding what is expected. I tried to trace through the reader/parsing code and it looks like the SharpYaml representation has the expected reference from AllPets to Pets, but by the time the OpenApiDocument gets returned from the reader.Read() call, the Components.Schemas["AllPets"] entry is incorrect.

[darrelmiller]

I'll need to dig into this a bit further but there is something in your example that does not look right. The way schema resolution works is references are replaced with the object they point to. Therefore schema1 and schema2 become the same object instance. That is why the Reference Ids match. I'm not sure why schema2.UnresolvedReference is true though.

[ShaunLoganOracle]

Thanks for looking into this Darrel. If there is anything I can do to assist, let me know. I will attach the altered version of Pet Store doc here.
petstore-3.0-broken.json.txt

[darrelmiller]

I made some progress towards fixing this but the current solution loses the reference to AllPets and replaces it with a reference to Pets. That will work, but one of the goals of the library is that parsing should not be lossy, so I need to completely fix this.