Issue merging objects with AutoMapper

I found this post describing how to conditionally copy values over a destination object if they are not null.

Works great except for list members, it always overwrites them with an empty list. I'm not sure if I've just not configured the mapper correctly or if this is a bug. The following program demonstrates the issue.

namespace automapper_test
{
    using AutoMapper;
    using System;
    using System.Collections.Generic;

    class Program
    {
        class Test
        {
            public int? A { get; set; }
            public string B { get; set; }
            public Guid? C { get; set; }
            public List<Guid> D { get; set; }
        }

        static void Main(string[] args)
        {
            var config = new MapperConfiguration(cfg =>
            {
                cfg.AllowNullCollections = true;
                cfg.CreateMap<Test, Test>().ForAllMembers(opt => opt.Condition((src, dest, member) => member != null));
            });

            var mapper = config.CreateMapper();

            var source = new Test { A = 2, C = Guid.Empty };
            var target = new Test { A = 1, B = "hello", C = Guid.NewGuid(), D = new List<Guid> { Guid.NewGuid() } };

            mapper.Map(source, target);

            System.Diagnostics.Debug.Assert(target.D.Count == 1);
        }
    }
}