Synchron calls after Asynchron calls with no result blocks forever

[MJE-GTI]

Describe the bug
When I call a sync WCF OperatinContract after an async OperationContract call with no result the synchron call is never resolved. If the perverious async call has a result this problem does not happen.

To Reproduce
Create a WCF Service with Async Methods that returns somsthing (Test1Async) and one that returns nothing (Test2Async) and add a sync Method (Test3)

[ServiceContract]
public interface ITestService
{
    [OperationContract]
    Task<string> Test1Async(string text);

    [OperationContract]
    Task Test2Async(string text);

    [OperationContract]
    string Test3(string text);
}

Call the WCF Interface (see code below with comments)

private static async Task CallNetPipeBinding(string hostAddr)
{
    IClientChannel channel = null;

    var binding = new NetNamedPipeBinding();

    var factory = new ChannelFactory<ITestService>(binding, new EndpointAddress($"{hostAddr}/netPipe"));
    await Task.Factory.FromAsync(factory.BeginOpen, factory.EndOpen, TaskCreationOptions.None);
    try
    {
        ITestService client = factory.CreateChannel();
        channel = client as IClientChannel;
        await Task.Factory.FromAsync(channel.BeginOpen, channel.EndOpen, TaskCreationOptions.None);

        await client.Test1Async("Test");
        client.Test3("Test");// This call works because the perverious call returns something
        await client.Test2Async("Test");
        client.Test3("Test");// This call does not work becausee the pereverious call returns nothing
    }
    finally
    {
        factory.Close();
    }
}

Expected behavior
Synchron calls after async call with no result don't block forever.

Additional context
I think the problem is that the TaskCompletionSource withtout result is not created with TaskCreationOptions.RunContinuationsAsynchronously

TaskCompletionSource Creation with return Type:

wcf/src/System.ServiceModel.Primitives/src/System/ServiceModel/Channels/ServiceChannelProxy.cs

Line 318 in c7b4036

return new TaskCompletionSource<T>(TaskCreationOptions.RunContinuationsAsynchronously);

wcf/src/System.ServiceModel.Primitives/src/System/ServiceModel/Channels/ServiceChannelProxy.cs

Line 174 in c7b4036

TaskCompletionSourceProxy tcsp = new TaskCompletionSourceProxy(operation.TaskTResult);

TaskCompletionSource Creation without return Type:

wcf/src/System.ServiceModel.Primitives/src/System/ServiceModel/Channels/ServiceChannelProxy.cs

Line 213 in c7b4036

TaskCompletionSource<object> tcs = new TaskCompletionSource<object>();

[mconnew]

Which package version are you using? I believe this was fixed in the last year or two.

[mconnew]

I believe this is the explanation of what's going on along with a workaround if you can't upgrade to a fixed version.
#4946 (comment)
Basically you do this:

        await client.Test1Async("Test");
        client.Test3("Test");// This call works because the perverious call returns something
        await client.Test2Async("Test");
        await Task.Yield();
        client.Test3("Test");// This call does not work becausee the pereverious call returns nothing

[MJE-GTI]

I tested it with the NuGet Packages Version 8.0.0 and with a local build of the master branch witch is less then a month old.
The Example in #4946 (comment) only uses Tasks with a result Task<T> and this works without any problems for me. But if my Task does not have a result Task is doesn't work.

[HongGit]

@imcarolwang can you please create a PR and add unit tests for this?