Make @ResponseStatus on a void controller advice method optional

extensions/spring-web/deployment/src/main/java/io/quarkus/spring/web/deployment/ControllerAdviceAbstractExceptionMapperGenerator.java

@@ -108,16 +108,14 @@ protected void preGenerateMethodBody(ClassCreator cc) {
     void generateMethodBody(MethodCreator toResponse) {
         if (returnType.kind() == Type.Kind.VOID) {
             AnnotationInstance responseStatusInstance = controllerAdviceMethod.annotation(RESPONSE_STATUS);
-            if (responseStatusInstance == null) {
-                throw new IllegalStateException(
-                        "void methods annotated with @ExceptionHandler must also be annotated with @ResponseStatus");
-            }
 
             // invoke the @ExceptionHandler method
             exceptionHandlerMethodResponse(toResponse);
 
             // build a JAX-RS response
-            ResultHandle status = toResponse.load(getHttpStatusFromAnnotation(responseStatusInstance));
+            ResultHandle status = toResponse
+                    .load(responseStatusInstance != null ? getHttpStatusFromAnnotation(responseStatusInstance)
+                            : Response.Status.NO_CONTENT.getStatusCode());
             ResultHandle responseBuilder = toResponse.invokeStaticMethod(
                     MethodDescriptor.ofMethod(Response.class, "status", Response.ResponseBuilder.class, int.class),
                     status);

extensions/spring-web/deployment/src/main/java/io/quarkus/spring/web/deployment/SpringWebProcessor.java

@@ -424,12 +424,6 @@ private void generateMappersForExceptionHandlerInControllerAdvice(
                 reflectiveClassProducer.produce(new ReflectiveClassBuildItem(true, true, returnTypeDotName.toString()));
             }
 
-            AnnotationInstance responseStatusInstance = method.annotation(RESPONSE_STATUS);
-            if ((method.returnType().kind() == Type.Kind.VOID) && (responseStatusInstance == null)) {
-                throw new IllegalStateException(
-                        "void methods annotated with @ExceptionHandler must also be annotated with @ResponseStatus");
-            }
-
             // we need to generate one JAX-RS ExceptionMapper per Exception type
             Type[] handledExceptionTypes = exceptionHandlerInstance.value().asClassArray();
             for (Type handledExceptionType : handledExceptionTypes) {

integration-tests/spring-web/src/main/java/io/quarkus/it/spring/web/CustomAdvice.java

@@ -18,6 +18,11 @@ public void handleRuntimeException() {
 
     }
 
+    @ExceptionHandler(UnannotatedException.class)
+    public void unannotatedException() {
+
+    }
+
     @ExceptionHandler(IllegalStateException.class)
     public ResponseEntity<Error> handleIllegalStateException(IllegalStateException e,
             HttpServletRequest request, HttpServletResponse response) {

integration-tests/spring-web/src/main/java/io/quarkus/it/spring/web/ExceptionThrowingController.java

@@ -24,6 +24,11 @@ public void runtimeException() {
         throw new RuntimeException();
     }
 
+    @GetMapping("/unannotated")
+    public void unannotated() {
+        throw new UnannotatedException();
+    }
+
     @GetMapping("/responseEntity")
     public Greeting handledByResponseEntity() {
         throw new IllegalStateException("bad state");

integration-tests/spring-web/src/main/java/io/quarkus/it/spring/web/UnannotatedException.java

@@ -0,0 +1,4 @@
+package io.quarkus.it.spring.web;
+
+public class UnannotatedException extends RuntimeException {
+}

integration-tests/spring-web/src/test/java/io/quarkus/it/spring/web/SpringControllerTest.java

@@ -69,6 +69,14 @@ public void testExceptionHandlerVoidReturnType() {
                 .statusCode(400);
     }
 
+    @Test
+    public void testExceptionHandlerWithoutResponseStatusOnExceptionOrMethod() {
+        RestAssured.when().get("/exception/unannotated").then()
+                .contentType("text/plain")
+                .body(isEmptyString())
+                .statusCode(204);
+    }
+
     @Test
     public void testExceptionHandlerResponseEntityType() {
         RestAssured.when().get("/exception/responseEntity").then()