title: Error on mapping an entity on another with a property more using Automapper
body: <p>I am trying to mapping a entity in another with similar properties but I would like to have a field more in my "destination type".
  I want to map a Entity that use the destination value for a null field of the source class and I don´t want to have all fields mapped on my source type.</p>
  
  <p>Have a look at the example:</p>
  
  <pre><code>[TestClass]
  public class Example
  {
    public class Person
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int? Foo { get; set; }
    }
  
    public class DPerson
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int? Foo { get; set; }
        public bool IsUser { get; set; }
    }
  
    [TestMethod]
    public void TestNullIgnore()
    {
        Mapper.CreateMap&lt;Person, DPerson&gt;()
            .ForAllMembers(opt =&gt; opt.Condition(srs =&gt; !srs.IsSourceValueNull));
  
        var sourcePerson = new Person
        {
            FirstName = "Bill",
            LastName = "Gates",
        };
        var destinationPerson = new DPerson
        {
            FirstName = "",
            LastName = "",
            Foo = 1,
            IsUser = true
        };
        Mapper.Map(sourcePerson, destinationPerson);
  
        Assert.IsNotNull(destinationPerson);
        Assert.AreEqual(1, destinationPerson.Foo);
        Assert.AreEqual(true, destinationPerson.IsUser);
    }
  } 
  </code></pre>
  
  <p>When I added IsUser property at DPerson class The AutoMapper throws an odd exception "AutoMapper.AutoMapperMappingException" and in its message it said that it is not possible to map "Person -> Boolean".</p>
  
  <p>If I remove ".ForAllMembers(opt => opt.Condition(srs => !srs.IsSourceValueNull))" configuration it works but I got "null" at the Foo property.</p>
  
  <p>I adpated the code of the first answer for this question: <a href="https://stackoverflow.com/questions/12514084/automapper-map-ignore-all-null-value-properties-from-source-object">AutoMapper.Map ignore all Null value properties from source object</a> </p>
  
  <p>Can anyone help me?</p>
  
  <p>Cheers.</p>