[BUG][Java][jaxrs-spec] When using discriminator, enum properties of children are defined in parent instead of child class

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When I define a schema with discriminator and a child has an enum property, the enum definition and the property is generated into the parent and therefore available for all other children. This also results in a compile error when generating the equals and hashCode methods.

This issue is currently blocking any updates of this generator for me.

openapi-generator version

I tried the latest master (7.7.0-20240520.095624). It worked with 7.2.0 and is broken since 7.3.0

OpenAPI declaration file content or url

https://gist.github.com/Gerschtli/197faf5d172bcaf63d08cedaa364107f

Generation Details

java -jar openapi-generator.jar generate -g jaxrs-spec -i spec.yaml

Steps to reproduce

Use provided spec.yaml and generate java code with the command from above.

Related issues/PRs

I did not find any related Issues/PRs.

Suggest a fix

I don't have any workaround. As this is currently blocking me, any workaround would be appreciated!

Start by running java -jar openapi-generator.jar generate -g jaxrs-spec -i spec.yaml with the specification from the linked gist and compare the generated parent and child classes. Trace Java jaxrs-spec generation around the regression introduced after version 7.2.0; done means the enum property is defined only on its child and the generated equals and hashCode code compiles.