.Net client generate DataContract cache overflow exception when return type is nullable ValueTuple

[Diesel1017]

Bug description

Conditions for causing an error:

• When binding is NetTcp. (not 100% sure that only then)
• The interface call return type is nullable valuetuple and has return value.
  e.g:
  public (double value, string textValue)? TestCall()

When return value is (12, "SomeText doesn't matter") then:

• With .NET Framework 4.8.1: Works without errors
• With .NET (tested with 6-8): Throws exception.

The exception:
System.ServiceModel.Dispatcher.NetDispatcherFaultException: 'The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter http://Microsoft.Samples.NetTcp:ValueTupleTestResult. The InnerException message was 'An internal error has occurred. DataContract cache overflow.'. Please see InnerException for more details.'

To Reproduce

Call wcf service with .net client nullable valuetuple method.

1. I attached a sample project. Sample.zip (Don't forget change the target to .net)
2. The full callstack:
   System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameterPart(System.Xml.XmlDictionaryReader reader, System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo part, bool isRequest) System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeParameter(System.Xml.XmlDictionaryReader reader, System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.PartInfo part, bool isRequest) System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.DeserializeBody(System.Xml.XmlDictionaryReader reader, System.ServiceModel.Channels.MessageVersion version, string action, System.ServiceModel.Description.MessageDescription messageDescription, object[] parameters, bool isRequest) System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.OperationFormatter.DeserializeBodyContents(System.ServiceModel.Channels.Message message, object[] parameters, bool isRequest) System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.OperationFormatter.DeserializeReply(System.ServiceModel.Channels.Message message, object[] parameters) System.ServiceModel.Primitives.dll!System.ServiceModel.Dispatcher.ProxyOperationRuntime.AfterReply(ref System.ServiceModel.Dispatcher.ProxyRpc rpc) System.ServiceModel.Primitives.dll!System.ServiceModel.Channels.ServiceChannel.HandleReply(System.ServiceModel.Dispatcher.ProxyOperationRuntime operation, ref System.ServiceModel.Dispatcher.ProxyRpc rpc) System.ServiceModel.Primitives.dll!System.ServiceModel.Channels.ServiceChannel.Call(string action, bool oneway, System.ServiceModel.Dispatcher.ProxyOperationRuntime operation, object[] ins, object[] outs, System.TimeSpan timeout) System.ServiceModel.Primitives.dll!System.ServiceModel.Channels.ServiceChannel.Call(string action, bool oneway, System.ServiceModel.Dispatcher.ProxyOperationRuntime operation, object[] ins, object[] outs) System.ServiceModel.Primitives.dll!System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(System.ServiceModel.Channels.MethodCall methodCall, System.ServiceModel.Dispatcher.ProxyOperationRuntime operation) System.ServiceModel.Primitives.dll!System.ServiceModel.Channels.ServiceChannelProxy.Invoke(System.Reflection.MethodInfo targetMethod, object[] args) ProxyBuilder!generatedProxy_1.ValueTupleTest(double value, double value) client.dll!Microsoft.Samples.NetTcp.CalculatorClient.ValueTupleTest(double n1, double n2) Line 134 at D:\source\client\Connected Services\Microsoft.Samples.NetTcp\Reference.cs(134) client.dll!Microsoft.Samples.NetTcp.Client.Main() Line 41 at D:\source\client\client.cs(41)

Expected behavior
It should work the same way as in the .net framework.

[imcarolwang]

This appears to be a bug in the serialization code within the dotnet/runtime repository. I’ve opened a corresponding issue there: dotnet/runtime#119486