oauth2 redirect url calculated incorrectly when springdoc.swagger-ui.path=/

[philsttr]

Describe the bug
When springdoc.swagger-ui.path=/, the oauth2 redirect url is incorrectly calculated as http:/webjars/swagger-ui/oauth2-redirect.html

To Reproduce

spring boot 2.4.2
springdoc-openapi-webflux-ui 1.5.2

Configure springdoc.swagger-ui.path=/

Start application

Hit http://host:port/ first. (it is important that this url is hit first, before any other urls, for the bug to reproduce)

Then hit http://host:port/v3/api-docs/swagger-config

Notice "oauth2RedirectUrl": "http:/webjars/swagger-ui/oauth2-redirect.html",

Expected behavior

I expect oauth2RedirectUrl to be http://host:port/webjars/swagger-ui/oauth2-redirect.html",

Additional context

I believe the problem is here:

springdoc-openapi/springdoc-openapi-webflux-ui/src/main/java/org/springdoc/webflux/ui/SwaggerWelcomeCommon.java

Line 111 in 8d0aaea

url = url.replace(request.getPath().toString(), "");

In this case, request.getPath().toString == '/', so "http:host:port" is assigned to the url variable, which screws up the downstream logic.

[bnasslahsen]

@philsttr,

Thank for your investigation.
This should be fixed for the next release v1.5.3 that will be released in few hours.

BTW, i have also added the support for spring.webflux.base-path.