[OpenAPI] Duplicated object definitions in openapi spec

[januszj]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When using two classes as result from minimal api, that are using same class, openapi definition contains two copies of the object for example: WeatherForecast and WeatherForecast2.

"components": {
    "schemas": {
      "WeatherForecast": {
        "required": [
          "date",
          "temperatureC",
          "summary"
        ],
        "type": "object",
        "properties": {
          "date": {
            "type": "string",
            "format": "date"
          },
          "temperatureC": {
            "type": "integer",
            "format": "int32"
          },
          "summary": {
            "type": "string",
            "nullable": true
          },
          "temperatureF": {
            "type": "integer",
            "format": "int32"
          }
        },
        "nullable": true
      },
      "WeatherForecast2": {
        "required": [
          "date",
          "temperatureC",
          "summary"
        ],
        "type": "object",
        "properties": {
          "date": {
            "type": "string",
            "format": "date"
          },
          "temperatureC": {
            "type": "integer",
            "format": "int32"
          },
          "summary": {
            "type": "string",
            "nullable": true
          },
          "temperatureF": {
            "type": "integer",
            "format": "int32"
          }
        }
      },

I created reproduction sample code.

WebApplication3.zip

Expected Behavior

It should generated schema with one WeatherForecast.

Steps To Reproduce

Run repo project, open scalar and click Download OpenAPI Document

Exceptions (if any)

No response

.NET Version

9.0.5

Anything else?

No response