PropertyFetchingImpl getPropertyViaFieldAccess algorithm cannot find private fields on abstract classes

[meostyles]

PropertyFetchingImpl#getPropertyViaFieldAccess first looks for the field with Class#getField where it will not find the field because internally it calls Class#privateGetDeclaredFields(publicOnly: true). This method does however try to handle if the field is on a superclass

// Direct superclass, recursively
  if (!isInterface()) {
      Class<?> c = getSuperclass();
      if (c != null) {
          if ((res = c.getField0(name)) != null) {
              return res;
          }
      }
  }

The PropertyFetchingImpl then uses Class#getDeclaredField to access private fields via setAccessible. The problem is, although that method does call Class#privateGetDeclaredFields(publicOnly: false), it does not have any handling to look for the field on the superclass.

As such, Spring for GraphQL can resolve fields like so (without any public getters)

public class MyClass {
    private final ImmutableList<Id> ids;
}

but not fields like so (without any public getters)

public abstract class MyAbstractClass {
    private final ImmutableList<Id> ids;
}