Dependency cycle with SAMLEntryPoint

[OrangeDog]

There's a dependency cycle between SAMLDiscovery.setSamlEntryPoint and SAMLEntryPoint.setSamlDiscovery.
This generates an error on startup as of Spring Boot 2.6.

The dependencies of some of the beans in the application context form a cycle:

   samlFilter
┌─────┐
|  samlEntryPoint
↑     ↓
|  samlDiscovery
└─────┘

Workaround is to set spring.main.allow-circular-references=true.

[wilkinsona]

This could also affect users of earlier Spring Boot versions or of plain Spring Framework if they've set AbstractAutowireCapableBeanFactory.setAllowCircularReferences(boolean) to false as Boot does by default as of 2.6.

[gertjanal]

Workaround for Spring Boot:

final SpringApplicationBuilder builder = new SpringApplicationBuilder(applicationClass)
    .allowCircularReferences(true)
    ...