Regression in Jetty 12.1: Invalid UTF-8 exception for application/x-www-form-urlencoded; charset=iso-8859-1

[kelunik]

Jetty version(s)
12.1.7 (12.1.x)

Jetty Environment
core

HTTP version
2

Java version/vendor (use: java -version)
25 Corretto

OS type/version
any

Description

Jetty 12.1.7 doesn't correctly handle ISO-8859-1 encoded requests and returns an error response instead of the expected 200 OK with the example below. The same code is working fine in Jetty 12.0.33.

How to reproduce?

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.kelunik</groupId>
    <artifactId>jetty-bug-charset</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>25</maven.compiler.source>
        <maven.compiler.target>25</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.eclipse.jetty.http2</groupId>
            <artifactId>jetty-http2-server</artifactId>
            <version>12.1.7</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>2.0.17</version>
        </dependency>
    </dependencies>
</project>

package com.kelunik;

import org.eclipse.jetty.http2.server.HTTP2ServerConnectionFactory;
import org.eclipse.jetty.server.*;
import org.eclipse.jetty.util.Callback;

import java.nio.ByteBuffer;

public class Main {
    static void main() throws Exception {
        Server server = new Server();

        ServerConnector connector = new ServerConnector(server, new HTTP2ServerConnectionFactory());
        server.addConnector(connector);

        server.setHandler(new Handler.Abstract() {
            @Override
            public boolean handle(Request request, Response response, Callback callback) throws Exception {
                Request.getParameters(request);

                response.write(true, ByteBuffer.wrap(new byte[0]), callback);

                return true;
            }
        });

        server.start();
    }
}

curl --http2-prior-knowledge -v http://localhost:52240 -H 'content-type: application/x-www-form-urlencoded; charset=iso-8859-1' --data 'name=%e9'

See #14614 for a possible fix.

[joakime]

I'll take this one.

[kelunik]

@joakime Anything I can do? You hinted that there are problems with the current PR, apart from missing tests. Some more hints would be useful.

[joakime]

I've tested the low level Request.getParameters(request); handling with HTTP/1.1, using application/x-www-form-urlencoded;charset=iso-8859-1 in commit fb97d5c - No problems with this combination, it works as expected.

Now to see if the HTTP/2 specific behavior of your report could be the cause.

[kelunik]

@joakime As mentioned in #14614, it doesn't happen on HTTP/1.1, because the header field is an instance of MimeTypes.ContentTypeField there, so this code path isn't hit, and the issue isn't reproducible via HTTP/1.1.