ClientWebSocket.Connect hangs indefinitely if using HttpVersionPolicy.RequestVersionOrHigher on wss connections

[ArXen42]

Description

ClientWebSocket hangs when attempting to connect to HTTP/1.1 WebSocket server using RequestVersionOrHigher policy. If this is expected behavior, it should probably be documented.

Reproduction Steps

This will hang unless HttpVersionPolicy setting is commented out:

using System.Net.WebSockets;

using var ws = new ClientWebSocket();
ws.Options.HttpVersion       = new(1, 1);
ws.Options.HttpVersionPolicy = HttpVersionPolicy.RequestVersionOrHigher; // <--- causes problem

using var handler = new SocketsHttpHandler();
handler.ConnectTimeout = TimeSpan.FromSeconds(10);

using var invoker = new HttpMessageInvoker(handler);
await ws.ConnectAsync(new("wss://echo.websocket.org"), invoker, CancellationToken.None); // <-- hangs
Console.WriteLine(ws.State);

Expected behavior

Correctly determining that server doesn't support HTTP/2 and falling back to HTTP/1.1.

Actual behavior

Hangs indefinitely.

Regression?

Didn't test on .NET 7 yet, but seems to behave similarly on .NET 8 and .NET 9.

Known Workarounds

Using inverse options seems to work:

ws.Options.HttpVersion       = new(2, 0);
ws.Options.HttpVersionPolicy = HttpVersionPolicy.RequestVersionOrLower;

Configuration

Tested on .NET 8, 9: win-x64, linux-x64, linux-arm64.

Other information

No response

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

[MihaZupan]

I think this is due to a lack of () in our version selection code here:

runtime/src/libraries/System.Net.WebSockets.Client/src/System/Net/WebSockets/WebSocketHandle.Managed.cs

Lines 80 to 81 in d551abb

	if (!tryDowngrade && options.HttpVersion >= HttpVersion.Version20
	|| (options.HttpVersion == HttpVersion.Version11 && options.HttpVersionPolicy == HttpVersionPolicy.RequestVersionOrHigher && uri.Scheme == UriScheme.Wss))

Right now it's effectively
(!tryDowngrade && options.HttpVersion >= HttpVersion.Version20) || (the rest)
instead of
!tryDowngrade && (options.HttpVersion >= HttpVersion.Version20 || the rest)

So we just keep retrying H2.

Clearly we're lacking test coverage here.