AbstractAuthenticationFilterConfigurer: add defaultSuccessUrl() function which doesn't override the successHandler field, or the variant with successHandler parameter

[Hotvianskyi]

Type: Enhancement

Currently, when creating a builder chain for HttpSecurity, and building FormLoginConfigurer inside of formLogin() method, 2 builder methods can be called in one chain: defaultSuccessUrl().<...>.successHandler(). But in reality, they are incompatible, because defaultSuccessUrl() creates its own successHandler inside, and calls successHandler() as well.
So when we have these 2 orders in the chain:

1. defaultSuccessUrl().successHandler(): We lose the result of defaultSuccessUrl
2. .successHandler().defaultSuccessUrl(): We lose the result of successHandler

There are 2 possible solutions:

• create a variant for defaultSuccessUrl which does not override the successHandler
• create a variant for defaultSuccessUrl with successHandler as input parameter

[snicoll]

This isn't the right place to report an issue to Spring Security. Please use the appropriate project: https://github.com/spring-projects/spring-security