[BUG][JAVA] OpenAPI Generator fails on a recursive oneOf schema (boolean expression tree) when using OpenAPI 3.1.0.

Description

OpenAPI Generator fails on a recursive oneOf schema (boolean expression tree) when using OpenAPI 3.1.0. The generator crashes with a Jackson StreamWriteConstraints nesting depth error while parsing/traversing the schema (deep copy).
This prevents code generation even though the schema is valid and commonly used (tree recursion).

openapi-generator version

7.17.0 (Maven plugin). Unsure if regression.

OpenAPI declaration file content or url

A recursive schema with oneOf and discriminator. Minimal reproduction still needed, but the relevant pattern is:

openapi: 3.1.0
components:
schemas:
SearchQueryObject:
type: object
discriminator:
propertyName: type
mapping:
'AND': '#/components/schemas/BoolAnd'
'OR': '#/components/schemas/BoolOr'
'NOT': '#/components/schemas/BoolNot'
'search_text': '#/components/schemas/SearchQueryObjectNodeSearchText'
oneOf:
- $ref: '#/components/schemas/SearchQueryObjectNodeSearchText'
- $ref: '#/components/schemas/BoolAnd'
- $ref: '#/components/schemas/BoolOr'
- $ref: '#/components/schemas/BoolNot'

  BoolAnd:
    type: object
    properties:
      type:
        type: string
        enum: ['AND']
      nodes:
        type: array
        items:
          $ref: '#/components/schemas/SearchQueryObject'
    required: [type, nodes]
    additionalProperties: false

  BoolOr:
    type: object
    properties:
      type:
        type: string
        enum: ['OR']
      nodes:
        type: array
        items:
          $ref: '#/components/schemas/SearchQueryObject'
    required: [type, nodes]
    additionalProperties: false

  BoolNot:
    type: object
    properties:
      type:
        type: string
        enum: ['NOT']
      node:
        $ref: '#/components/schemas/SearchQueryObject'
    required: [type, node]
    additionalProperties: false

  SearchQueryObjectNodeSearchText:
    type: object
    properties:
      type:
        type: string
        enum: ['search_text']
      searchText:
        type: string
    required: [type, searchText]
    additionalProperties: false

Generation Details

Maven plugin:

• org.openapitools:openapi-generator-maven-plugin:7.17.0
• generatorName: spring
• inputSpec: ais-backend-api.yaml (includes external $ref to the schema above)

Steps to reproduce

1. Configure Maven plugin to generate Spring server code from the OpenAPI 3.1.0 spec.
2. Run mvn generate-sources (or plugin goal).

Actual output vs expected output

Actual: generator fails with Jackson nesting depth error while traversing schema:

java.lang.RuntimeException: com.fasterxml.jackson.databind.JsonMappingException:
Document nesting depth (1002) exceeds the maximum allowed (1000, from StreamWriteConstraints.getMaxNestingDepth())
(through reference chain: io.swagger.v3.oas.models.media.JsonSchema["oneOf"] -> ... -> ["nodes"] -> ["items"] -> ["oneOf"] -> ...)

Expected: generator should handle recursive schemas without blowing up (or provide a configuration option to raise max nesting depth).

Related issues/PRs

Not searched yet.

Start by reproducing the failure with the Maven plugin, generatorName spring, and the recursive OpenAPI 3.1 schema described in the issue, using mvn generate-sources. Trace the schema deep-copy or traversal path that reaches Jackson's nesting-depth error; done means recursive schemas generate successfully or the supported configuration behavior is clearly established.