ODataResourceDeserializerHelpers issues with ComplexTypes that have EdmModel navigation properties

[robertmclaws]

Assemblies affected

ASP.NET Core OData 7.6.1

Describe the Problem

ODataResourceDeserializerHelpers.GenerateNestedReadContext() does not account for ComplexTypes (types that aren't mapped to the model) that contain properties whose types DO map to the model. At this point, edmProperty will not be null, and the edmProperty.PropertyKind will be Navigation, BUT readContext.Path.NavigationSource will be null, leading to a NullReferenceException on the next line.

(As an aside, the equality checks on lines 58 & 80 should be replaced with the "is" keyword, they evaluate faster. That should really be done throughout the codebase at some point.)

Reproduce steps

1. Create an OData service with an endpoint that accepts a List<NotDatabaseObject> as a parameter.
2. Make a request to that endpoint with multiple NotDatabaseObjects in the payload.

Data Model

public class DatabaseObject
{
     public Guid Id { get; set; }
}

public class NotDatabaseObject
{
    public List<DatabaseObject> DatabaseObjects { get; set; } = new();
}

Expected behavior

I expect the request to be processed like it was in previous versions and for the service to produce a response.

Screenshots