False positive when adding optional property

When comparing these 2 schemas:

test/old.json

{
  "openapi": "3.0.0",
  "servers": [{ "url": "https://myserver.com" }],
  "info": { "title": "My API", "description": "Description", "version": "0.2.0" },
  "paths": {
    "/v1/entity/{id}": {
      "put": {
        "operationId": "myOperation",
        "description": "Some description",
        "requestBody": { "$ref": "#/components/requestBodies/updateBody" }
      }
    }
  },
  "components": {
    "schemas": {},
    "responses": {},
    "requestBodies": {
      "updateBody": {
        "description": "Update description",
        "content": {
          "application/json": {
            "schema": {
              "type": "object",
              "properties": {
                "url": { "type": "string", "description": "Some URL" }
              },
              "title": "updateBody",
              "additionalProperties": false
            }
          }
        }
      }
    },
    "parameters": {}
  }
}

test/new.json

{
  "openapi": "3.0.0",
  "servers": [{ "url": "https://myserver.com" }],
  "info": { "title": "My API", "description": "Description", "version": "0.2.0" },
  "paths": {
    "/v1/entity/{id}": {
      "put": {
        "operationId": "myOperation",
        "description": "Some description",
        "requestBody": { "$ref": "#/components/requestBodies/updateBody" }
      }
    }
  },
  "components": {
    "schemas": {},
    "responses": {},
    "requestBodies": {
      "updateBody": {
        "description": "Update description",
        "content": {
          "application/json": {
            "schema": {
              "type": "object",
              "properties": {
                "url": { "type": "string", "description": "Some URL" },
                "url2": { "type": "string", "description": "Some URL" }
              },
              "title": "updateBody",
              "additionalProperties": false
            }
          }
        }
      }
    },
    "parameters": {}
  }
}

I get a broken compatibility message:

docker run --rm -t -v $(pwd)/test/:/specs:ro openapitools/openapi-diff:latest --fail-on-incompatible  /specs/old.json /specs/new.json 
==========================================================================
==                            API CHANGE LOG                            ==
==========================================================================
                                  My API                                  
--------------------------------------------------------------------------
--                            What's Changed                            --
--------------------------------------------------------------------------
- PUT    /v1/entity/{id}
  Request:
        - Changed application/json
          Schema: Broken compatibility
--------------------------------------------------------------------------
--                                Result                                --
--------------------------------------------------------------------------
                 API changes broke backward compatibility                 
--------------------------------------------------------------------------

Note that the only change is the addition of the url2 optional property:

diff -u test/old.json test/new.json
--- test/old.json       2023-03-14 17:06:02
+++ test/new.json       2023-03-14 17:06:33
@@ -22,7 +22,8 @@
             "schema": {
               "type": "object",
               "properties": {
-                "url": { "type": "string", "description": "Some URL" }
+                "url": { "type": "string", "description": "Some URL" },
+                "url2": { "type": "string", "description": "Some URL" }
               },
               "title": "updateBody",
               "additionalProperties": false

Since the required field is absent, I would expect the addition of url2 to not create a broken compatibility error.

提供されたtest/old.jsonとtest/new.jsonのfixtureから始め、レポートに記載されたDockerコマンドを使って結果を再現します。必須フィールドのない追加プロパティに対するリクエストボディスキーマの互換性チェックを追跡し、その後リグレッションテストを追加して、比較結果で後方互換性のない変更が報告されなくなったことを確認します。