Custom favicon placed in static resources doesn't work since 2.2.0.M5

[vpavic]

After upgrading to Spring Boot 2.2.0.M5 custom favicon placed in src/main/resources/static/favicon.ico stopped working, and Boot's default favicon is returned instead.

At quick glance, I suspect this is a regression caused by #17318. It seems unintended, as this comment states that:

A custom favicon placed somewhere beneath a static resources location will also continue to work as it did before.

Which isn't the case, unless I misunderstood something.

This can be easily reproduced with a minimal application using just spring-boot-starter-web and having custom favicon placed in src/main/resources/static/favicon.ico. Downgrading to 2.2.0.M4 restores the expected behavior.

[wilkinsona]

When fixing #17318, I was too focused on the nested case, GET /explorer/favicon.ico for example, and did not consider the simpler and more common case of GET /favicon.ico. This simpler case is a direct match for the favicon.ico resource handler mapping to classpath:favicon.ico so the favicon found by the classpath, typically Boot's, is always returned.

[wilkinsona]

Thanks for trying out M5, @vpavic. This should now be fixed on master. You should be able to work around the problem with M5 by moving your favicon.ico into src/main/resources so that it can be found at the root of the classpath. Alternatively, you could set spring.mvc.favicon.enabled=false.

[vpavic]

Thanks for the prompt fix @wilkinsona. I did workaround this by disabling default favicon through environment. I'll give snapshot a try later today.