[Question] [Bug]: Inconsistent Relative Reference Resolution in Nested Schema Contexts

Question

There seems to be a bug when resolving nested schemas.

OpenAPI Generator incorrectly resolves relative $ref paths in schema files when they are referenced through nested contexts (like additionalProperties). The reference resolution context switches from file-relative to root-relative depending on the nesting level, causing build failures when using standard file-relative references.

This creates inconsistent behavior where:

References from path files work correctly using file-relative paths (../components/schemas/...)
References from schema files fail when using file-relative paths (NestedData.yaml)

This violates the OpenAPI 3.0 specification where all relative references should be resolved from the containing file's location.

Any ideas? parentDirectory seems to be resolved wrongly in this case?

Affected Version

Latest

Context

This issue first reported here: https://github.com/OpenAPITools/openapi-generator/issues/21492 (the project uses this library)

# Example OpenAPI or Swagger definition (optional)

Additional Details

Checklist

• I have searched the existing issues and documentation before asking.
• I have provided enough information for others to understand my question.

Start with the reproduction context in OpenAPITools/openapi-generator#21492 and inspect how parentDirectory is handled while resolving relative $ref values through nested additionalProperties schemas. Verify the behavior against the OpenAPI 3.0 file-relative rule, including both path-file and schema-file references; done means nested references resolve consistently without build failures.