NullPointerException when Host header is not defined in HTTP/1.0 requests

[syntonyze]

Jetty version

jetty-9.4.32.v20200930

Java version

openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment (build 11.0.8+11)
OpenJDK 64-Bit Server VM (build 11.0.8+11, mixed mode)

OS type/version

MacOS Catalina 10.15.7

Description

I believe change [1] might have introduced a regression.

HTTP/1.0 does not require a Host: header, however, when such an HTTP request is made jetty throws a NullPointerException.

This is the stacktrace of the error:

2020-11-24T16:14:16.676+01:00	java.lang.NullPointerException
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.server.ForwardedRequestCustomizer.customize(ForwardedRequestCustomizer.java:523)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:379)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:375)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:773)
2020-11-24T16:14:16.676+01:00	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:905)
2020-11-24T16:14:16.676+01:00	at java.base/java.lang.Thread.run(Thread.java:834)

This is very likely to happen through haproxy's health checks requests[2], which are not setting any header by default, not even the Host header.

[1]ac42cbd#diff-86a904c7dd1271f369ee7e75efbdcc7a1131708dad3df125327faa31a3c81c5eR508

[2]https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#option%20httpchk

[joakime]

Duplicate of #5443
Fixed in Jetty 9.4.33.v20201020