quarkus: Hibernate Reactive / Reactive Messaging Transaction issue on constraint violation

Describe the bug

I have a very simple application using RestEasy Reactiv, Reactive Messaging (no connector, just plain in-memory), and Hibernate Reactive with PostgreSQL.

My application has an endpoint doing this:

@Channel("database")
MutinyEmitter<Person> emitter;

@POST
public Uni<Response> upload(Person person) {
    return emitter.send(person)
            .replaceWith(Response.accepted().build())
            .onFailure().recoverWithItem(t -> 
                  Response.status(Response.Status.BAD_REQUEST).entity(t.getMessage()).build()
     );
}

Basically, it gets a Person and sends it to the database channel.

The database channel is read as follows:

@Incoming("database")
public Uni<Void> write(Person person) {
      return Panache.withTransaction(person::persist);
}

Everything works fine until I add a constraint in my entity and that constraint gets violated:

@Entity
public class Person extends PanacheEntity {

    @Column(unique = true)
    public String name;

}

It works until I deliberately send a payload violating the constraint. I got the 400 error, but any subsequent request gets the same issue, with the same error message:

> http POST :8080 name=a
HTTP/1.1 202 Accepted
content-length: 0

> http POST :8080 name=a # Exception expected
HTTP/1.1 400 Bad Request
Content-Type: application/octet-stream
content-length: 555

Multiple exceptions caught:
	[Exception 0] javax.persistence.PersistenceException: org.hibernate.HibernateException: io.vertx.pgclient.PgException: { "message": "duplicate key value violates unique constraint \"uk_is4vd0f6kw9sw4dxyie5cy9fa\"", "severity": "ERROR", "code": "23505", "detail": "Key (name)=(a) already exists.", "file": "nbtinsert.c", "line": "656", "routine": "_bt_check_unique", "schema": "public", "table": "person", "constraint": "uk_is4vd0f6kw9sw4dxyie5cy9fa" }
	[Exception 1] io.vertx.core.VertxException: Transaction already completed

> http POST :8080 name=b
HTTP/1.1 400 Bad Request
Content-Type: application/octet-stream
content-length: 555

Multiple exceptions caught:
	[Exception 0] javax.persistence.PersistenceException: org.hibernate.HibernateException: io.vertx.pgclient.PgException: { "message": "duplicate key value violates unique constraint \"uk_is4vd0f6kw9sw4dxyie5cy9fa\"", "severity": "ERROR", "code": "23505", "detail": "Key (name)=(a) already exists.", "file": "nbtinsert.c", "line": "656", "routine": "_bt_check_unique", "schema": "public", "table": "person", "constraint": "uk_is4vd0f6kw9sw4dxyie5cy9fa" }
	[Exception 1] io.vertx.core.VertxException: Transaction already completed

So even when sending b, it still complains about a. It seems like it didn’t clean up after the transaction rollback. I have checked that all the calls used the same MutinySession, but the transaction objects are different.

To Reproduce

reproducer-rm-hr.zip

To reproduce, just run the test included in the project above ^ Or in a terminal

mvn clean quarkus:dev

and, in another terminal:

http POST :8080 name=bob # expected 202
http POST :8080 name=bob # expected 400 - name is not unique
http POST :8080 name=tom # expected 202, but got 400, with the same error message than the previous request