Missing Etag header using custom @RepositoryRestController [DATAREST-1201]

Daniele Renda opened DATAREST-1201 and commented

I'm using Spring Boot 1.5.10, Spring Data REST, Spring HEATEOAS, Spring HPA. I created a custom GET method in my @RepositoryRestController like this:

@GetMapping(path = "/users/{id}")
    public ResponseEntity<?> findById(@PathVariable(value = "id") long userId, Locale locale,
            PersistentEntityResourceAssembler resourceAssembler) {
        Authentication auth = SecurityContextHolder.getContext().getAuthentication();
        //My implementation

        return new ResponseEntity<>(resourceAssembler.toResource(user), HttpStatus.OK);
    }

Unfortunately, differently from the default Spring Data REST repository the Etag header is missing.

Am I missing something? Is this behaviour desired?

Affects: 3.0.3 (Kay SR3)