Object reference not set to an instance of an object

[sybaris]

Describe the bug
An exception "Object reference not set to an instance of an object" is thrown when using a particular fetchxml

To Reproduce
Execute the following code to reproduce the issue

    [Microsoft.Xrm.Sdk.Client.EntityLogicalNameAttribute("solutioncomponent")]
    public partial class SolutionComponent : Microsoft.Xrm.Sdk.Entity
    {
        public SolutionComponent() : base("solutioncomponent")
        {
        }

        [Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("solutionid")]
        public Microsoft.Xrm.Sdk.EntityReference SolutionId
        {
            get
            {
                return this.GetAttributeValue<Microsoft.Xrm.Sdk.EntityReference>("solutionid");
            }
        }
    }

    [Microsoft.Xrm.Sdk.Client.EntityLogicalNameAttribute("solutioncomponentdefinition")]

    public class SolutionComponentDefinition : Microsoft.Xrm.Sdk.Entity
    {
        public SolutionComponentDefinition() : base("solutioncomponentdefinition")
        {
        }

        [Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("name")]
        public string Name
        {
            get
            {
                return this.GetAttributeValue<string>("name");
            }
            set
            {
                this.SetAttributeValue("name", value);
            }
        }
        [Microsoft.Xrm.Sdk.AttributeLogicalNameAttribute("objecttypecode")]
        public System.Nullable<int> ObjectTypeCode
        {
            get
            {
                return this.GetAttributeValue<System.Nullable<int>>("objecttypecode");
            }
            set
            {
                this.SetAttributeValue("objecttypecode", value);
            }
        }
    }


    [TestClass]
    public sealed class Test1
    {
        public static IXrmFakedContext CreateXrmFakedContext()
        {
            var context = MiddlewareBuilder
                        .New()
                        .AddCrud()
                        .AddFakeMessageExecutors()
                        .AddFakeMessageExecutors(Assembly.GetAssembly(typeof(RetrieveVersionRequestExecutor)))
                        .UseCrud()
                        .UseMessages()
                        .SetLicense(FakeXrmEasyLicense.RPL_1_5)
                        .Build();
            context.EnableProxyTypes(Assembly.GetExecutingAssembly());

            return context;
        }


        [TestMethod]
        public void TestNominal()
        {
            // Arrange
            var context = CreateXrmFakedContext();

            string fetchxml = @"
  <fetch xmlns:generator='MarkMpn.SQL4CDS'>
                 <entity name='solutioncomponent'>
                   <attribute name='solutionid' />
                   <link-entity name='solutioncomponentdefinition' to='componenttype' from='objecttypecode' alias='solutioncomponentdefinition' link-type='outer'>
                     <attribute name='name' alias='solutioncomponentdefinitionname'/>
                   </link-entity>
                   <filter>
<condition attribute = 'name' entityname='solutioncomponentdefinition' operator='eq' value='AppElement'/>
                   </filter>
                 </entity>
               </fetch>
";
            context.GetOrganizationService().RetrieveMultiple(new FetchExpression(fetchxml));
        }
    }

Expected behavior
No exception, and get the result

Version
FakeXrmEasy.v9 3.6.0

Notes
The problem is here :

When we enter in the method, attributeName="name". But after substring, attributeName is empty

I think a code like this can solve the issue :

[jordimontana82]

Thank you @sybaris , I'll take a look and I'll get back to you