Spring ResolvableType.forInstance should return NONE for null instance

ResolvableType.forInstance(Object) enforces a not-null argument which makes it unpleasant to use with input that can come from a nullable source (or even just an API call which in some circumstances may return null and is therefore marked as @Nullable, even if never actually null in a given usage scenario). A more usage-friendly variant is to accept null but turn it into ResolvableType.NONE.

Comment From: salmansharifov

@jhoeller Can I take this issue?

Comment From: jhoeller

@salmansharifov Thanks for volunteering but I got this locally prepared along with a few other backports to 5.3.22 already, to be committed today.