Possible Regression: RecursionError validating oneOf/allOf schema in 0.7.2 (works in 0.7.1)

Start by running the supplied validate.py reproduction with openapi-spec-validator 0.7.2, then compare it with 0.7.1 as shown. Trace the RecursionError from the validate(parsed_spec) entry point through the oneOf/allOf and $ref schema validation, and consider the issue done when the reproduction validates successfully without recursion failure while preserving the 0.7.1 result.

Summary

An OpenAPI 3.1 schema that validated fine with openapi-spec-validator 0.7.1 now fails with a RecursionError in 0.7.2

Environment

openapi-spec-validator | 0.7.2 ❌ / 0.7.1 ✅
uv 0.7.3 (3c413f74b 2025-05-07)

Minimal reproduction

# validate.py
# /// script
# requires-python = ">=3.12"
# dependencies = [
#    "openapi-spec-validator==0.7.2" # TODO: test with 0.7.1
# ]
# ///


import yaml
from openapi_spec_validator import validate

openapi_spec = """
openapi: 3.1.0
info:
  title: Recursion Bug Demo
  version: 0.1.0
components:
  schemas:
    PropertyConstraint:
      type: object
      oneOf:
        - $ref: '#/components/schemas/PropertyEqualityConstraint'
        - $ref: '#/components/schemas/PropertyRangeConstraint'
      properties:
        property_id:
          type: string
        type:
          type: string
      required: [type]

    PropertyEqualityConstraint:
      allOf:
        - $ref: '#/components/schemas/PropertyConstraint'
        - type: object
          properties:
            property_id:
              type: string
            property_value: {}
          required: [property_id, property_value]

    PropertyRangeConstraint:
      allOf:
        - $ref: '#/components/schemas/PropertyConstraint'
        - type: object
          properties:
            property_id:
              type: string
            min: {}
            max: {}
          required: [property_id, min, max]
"""


parsed_spec = yaml.safe_load(openapi_spec)
validate(parsed_spec)
print("valid")

> uv run validate.py
RecursionError: maximum recursion depth exceeded

Set the version to 0.7.1 in the uv script tag at the top.

> uv run validate.py
valid

Has anyone else observed this behaviour?