Scalar breaks X-Forwarded-For

[w-ronin]

Describe the bug

request.getHeader("X-Forwarded-For") is null with springdoc-openapi-starter-webmvc-scalar
All is fine with springdoc-openapi-starter-webmvc-ui.

To Reproduce
Steps to reproduce the behavior:

• What version of spring-boot you are using? 3.5.6
• What modules and versions of springdoc-openapi are you using? 2.8.13

Expected behavior

• A clear and concise description of what you expected to happen.
  XFF-header schould not be null.

[Mattias-Sehlstedt]

I believe it is tied to https://docs.spring.io/spring-security/reference/features/exploits/http.html#http-proxy-server and more specifically ForwardedHeaderFilter. You should be able to inject a configured bean to replace this bean.

As for an answer to why the default behavior differs for Scalar, I leave to the maintainer of the project to bring clarity to.