NullpointerException WebApplicationException when Response Headers not set

[YassineALLAL]

When mapping a WebApplicationException whose response returns null for getHeaders, an NPE is thrown and the original exception informaiton is lost.

To Reproduce

• Quarkus version: 3.5.2
• quarkus-resteasy-problem 3.1.0

Use a rest client that returns null headers instead of an empty map (in my case, keycloak admin client).

    @Path("reproduce")
    @GET
    public RealmRepresentation reproduce() {
        return KeycloakBuilder.builder()
                .serverUrl("http://keycloak.obsidian.com")
                .clientId("admin-cli")
                .realm("404")
                .username("user")
                .password("password")
                .build()
                .realm("404")
                .toRepresentation();
    }

{
    "details": "Error id 44fbd7fa-b5c8-4c5e-87bf-91492cbd4d12-4, java.lang.NullPointerException: Cannot invoke \"jakarta.ws.rs.core.MultivaluedMap.forEach(java.util.function.BiConsumer)\" because the return value of \"jakarta.ws.rs.core.Response.getHeaders()\" is null",
    "stack": "java.lang.NullPointerException: Cannot invoke \"jakarta.ws.rs.core.MultivaluedMap.forEach(java.util.function.BiConsumer)\" because the return value of \"jakarta.ws.rs.core.Response.getHeaders()\" is null\n\tat com.tietoevry.quarkus.resteasy.problem.jaxrs.WebApplicationExceptionMapper.toProblem(WebApplicationExceptionMapper.java:28)\n\tat com.tietoevry.quarkus.resteasy.problem.jaxrs.WebApplicationExceptionMapper.toProblem(WebApplicationExceptionMapper.java:13)\n\tat com.tietoevry.quarkus.resteasy.problem.ExceptionMapperBase.toResponse(ExceptionMapperBase.java:23)\n\tat org.jboss.resteasy.reactive.server.core.RuntimeExceptionMapper.mapException(RuntimeExceptionMapper.java:100)\n\tat org.jboss.resteasy.reactive.server.core.ResteasyReactiveRequestContext.mapExceptionIfPresent(ResteasyReactiveRequestContext.java:337)\n\tat org.jboss.resteasy.reactive.server.handlers.ExceptionHandler.handle(ExceptionHandler.java:15)\n\tat io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:150)\n\tat org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)\n\tat io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:582)\n\tat org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2513)\n\tat org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1538)\n\tat org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)\n\tat org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)\n\tat io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)\n\tat java.base/java.lang.Thread.run(Thread.java:840)"
}

Expected behavior
Null headers should be handled gracefully:

{
    "status": 404,
    "title": "Not Found",
    "detail": "Received: 'Server response is: 404' when invoking: Rest Client method: 'org.keycloak.admin.client.token.TokenService#grantToken'",
    "instance": "/reproduce"
}

[lwitkowski]

@YassineALLAL I've just released the fix for this as https://github.com/TietoEVRY/quarkus-resteasy-problem/releases/tag/v3.7.0 and https://github.com/TietoEVRY/quarkus-resteasy-problem/releases/tag/v3.9.0 (depending on which Quarkus version is used). Thanks for reporting this!

[YassineALLAL]

@lwitkowski Brilliant 🎉 thanks