This has been observed once in 9 b149 same binaries runs. Looks to be intermittent.

----------System.err:(22/1664)----------
java.util.concurrent.ExecutionException: java.io.IOException: Connection closed
at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:395)
at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1999)
at HttpInputStreamTest.main(HttpInputStreamTest.java:280)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:538)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:110)
at java.base/java.lang.Thread.run(Thread.java:844)
Caused by: java.io.IOException: Connection closed
at jdk.incubator.httpclient/jdk.incubator.http.Http1Response.readHeaders(Http1Response.java:69)
at jdk.incubator.httpclient/jdk.incubator.http.Http1Exchange.lambda$getResponseAsyncImpl$0(Http1Exchange.java:201)
at jdk.incubator.httpclient/jdk.incubator.http.internal.common.Utils.lambda$singleThreadExecutor$5(Utils.java:442)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1161)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
... 1 more