[BUG] Generating java code results in double models model.java, model1.java etc.

Description

In our contract, we use $ref to point to shared models. If we use openapi:3.1.0 then it gives duplicate models in the java code we generate. For example, we have a Client.java and a Client1.java.

We have found that if we use $ref along with allOf: that we do not get duplicate models.

Is this a bug and is our use of allOf a correct solution?

openapi-generator version

We are using the npm wrapper "@openapitools/openapi-generator-cli": "^2.15.3".
I think this defaults to the latest version.

OpenAPI declaration file content or url

This results in Office.java and Office1.java
`type: object
title: IdentifiedClientOrRelation
properties:
id:
type: string
number:
type: string
name:
type: string
office:
$ref: '../../../openapi.yml#/components/schemas/Office'
required:

• id
• number
• name
  `

But this results in only Office.java

`type: object
title: IdentifiedClientOrRelation
properties:
id:
type: string
number:
type: string
name:
type: string
office:
allOf:
- $ref: '../../../openapi.yml#/components/schemas/Office'
required:

• id
• number
• name
  `

Generation Details

package.json
{ "name": "e2e", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "generate:server": "openapi-generator-cli generate -c generated-server-code/config.json" }, "author": "", "license": "ISC", "dependencies": { "@openapitools/openapi-generator-cli": "^2.15.3", "mustache": "^4.2.0" }, "devDependencies": { "rimraf": "^6.0.1" } }

Steps to reproduce

npm run generate:server

Related issues/PRs

Suggest a fix

Start with package.json and generated-server-code/config.json, then run npm run generate:server against the supplied openapi.yml examples. Compare Java output for a direct $ref and an allOf-wrapped $ref, and determine what behavior should prevent Office.java and Office1.java from being generated.