ADDITIONAL SYSTEM INFORMATION :
Reproduced on a range of platform:

Mac OS (latest) and JDK 21 latest
RedHat Linux (REHL) 9 and JDK 17.0.8+7-LTS

A DESCRIPTION OF THE PROBLEM :

Additional comments on the following existing issue:
https://bugs.openjdk.org/browse/JDK-8239117

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
This code always fails when the targetted server isn't able to handle the "Upgrade: h2c" header automatically sent by this request. Indeed, the server I've found crashes, and breaks the TCP connection right away (confirmed by testing with curl).

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Ideally, a retry with http 1.1 instead.
Else, raise a IOException or InterruptedException
ACTUAL -
Exception in thread "main" java.io.IOException: HTTP/1.1 header parser received no bytes
at java.net.http/jdk.internal.net.http.HttpClientImpl.send(HttpClientImpl.java:964)
at java.net.http/jdk.internal.net.http.HttpClientFacade.send(HttpClientFacade.java:133)
at Test.main(test.java:21)
Caused by: java.io.IOException: HTTP/1.1 header parser received no bytes
at java.net.http/jdk.internal.net.http.common.Utils.wrapWithExtraDetail(Utils.java:388)
at java.net.http/jdk.internal.net.http.Http1Response$HeadersReader.onReadError(Http1Response.java:590)
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver.checkForErrors(Http1AsyncReceiver.java:302)
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver.flush(Http1AsyncReceiver.java:268)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$LockingRestartableTask.run(SequentialScheduler.java:182)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$CompleteRestartableTask.run(SequentialScheduler.java:149)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(SequentialScheduler.java:207)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.io.EOFException: EOF reached while reading
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver$Http1TubeSubscriber.onComplete(Http1AsyncReceiver.java:601)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$ReadSubscription.signalCompletion(SocketTube.java:648)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$InternalReadSubscription.read(SocketTube.java:853)
at java.net.http/jdk.internal.net.http.SocketTube$SocketFlowTask.run(SocketTube.java:181)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(SequentialScheduler.java:207)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler.runOrSchedule(SequentialScheduler.java:280)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler.runOrSchedule(SequentialScheduler.java:233)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$InternalReadSubscription.signalReadable(SocketTube.java:782)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$ReadEvent.signalEvent(SocketTube.java:965)
at java.net.http/jdk.internal.net.http.SocketTube$SocketFlowEvent.handle(SocketTube.java:253)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.handleEvent(HttpClientImpl.java:1467)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.lambda$run$3(HttpClientImpl.java:1412)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.run(HttpClientImpl.java:1412)

---------- BEGIN SOURCE ----------
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.URI;
import java.net.URISyntaxException;
import java.time.Duration;
import java.io.IOException;

public class Test {
  public static void main(String[] args) throws URISyntaxException, IOException, InterruptedException {
    final var request = HttpRequest.newBuilder()
        .uri(new URI("http://url_to_weird_server"))
        .GET()
        .timeout(Duration.ofSeconds(10))
        .build();

    var httpClient = HttpClient.newBuilder().build();

    var r = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
  }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
The workaround is to set `.version(HttpClient.Version.HTTP_1_1)` after line 12 in this particular case.

(setting the version to HttpClient.Version.HTTP_2, always leads to the issue, as expected snce this is the default behaviour)

FREQUENCY : always