Cyclic dependency with common base type swallows attributes

Hello,

I recently discovered a bug in Swagger-Core affecting object property resolution. As far as I could debug, it is related to a short circuit in object traversal to prevent StackOverflows - see ModelResolver:394. I could obersve the problem for two objects with a cyclic dependency on each other, whilst sharing a common base type and forcing the OpenAPI generator to traverse the object tree in a specific order using the allOf attribute.

I was able to provide a minimal reproduction in this repository: https://github.com/drakenfly/swagger-inheritance-bug

Performing a mvn clean install in the root of the project will generate an OpenAPI spec in api/target/generatedtest/openapi.[json|yaml].

This spec contains an object called PortfolioViewDto that should contain a list of DepotViewDto, which is missing. Navigating to api/src/main/java/rest/TestEndpoint.java and uncommenting the additional methods (and importing the DTOs of course) will lead to a correct generation of the spec file, as the order of traversal changes with the additional methods.

Is anybody here able to help?

Kind regards

Start with the minimal reproduction repository and run mvn clean install to generate api/target/generatedtest/openapi.[json|yaml]. Inspect the object traversal short circuit at ModelResolver:394 and compare the spec with and without the additional methods in api/src/main/java/rest/TestEndpoint.java. Done means PortfolioViewDto contains its expected list of DepotViewDto without relying on traversal order.