HttpClient from HttpClientFactory deadlocks in [WebMethod] called from Angular

[marcpaulv]

My setup

• ASP.NET WebForms using .NET framework 4.6.1
• Angular 1.6.6
• IHttpClientFactory implementation from Microsoft.Extensions.Http both version 2.1.1 & 2.2.0-preview3-35497

When making a request from Angular to a server-side method that in turns makes an HTTP request using an HttpClient obtained from the IHttpClientFactory implementation, the application deadlocks.
It's worth mentioning that if instantiating an HttpClient manually, the method does not deadlock.

In order to use IHttpClientFactory outside a netcoreapp2.0 project, I've used the following code:

IServiceCollection services = new ServiceCollection();
services.AddHttpClient();
ServiceProvider serviceProvider = services.BuildServiceProvider();
IHttpClientFactory _factory = serviceProvider.GetService<IHttpClientFactory>();

To Reproduce

Steps to reproduce the behavior:
Call the Load method from an Angular controller:

[WebMethod]
public static async Task> Load()
{
var data = await GetDataAsync().ConfigureAwait(false);

}
private static async Task<HttpResponseMessage> GetDataAsync()
{
HttpClient client = _factory.CreateClient();
// client = new HttpClient();
return await client.GetAsync("http://www.google.com").ConfigureAwait(false);
}

Expected behavior

The method GetDataAsync() returns.

Actual Behavior

The method GetDataAsync hangs, most probably deadlocking.
Note that if uncommenting the line client = new HttpClient(); the method does not hang anymore.

[rynowak]

This looks like another repo of #999 - which was fixed recently. If you need a workaround for this, you could solve it by removing our logging message handlers from the services after calling AddHttpClient. That will remove our logging support, which is the root cause of the bug.