title: Adding @ModelAttribute results in 400 (Bad Request) in Delete Request
body: <p>I can submit a delete request fine with the following:</p>
  
  <pre><code>@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
  public ResponseEntity&lt;Result&gt; deleteTest(@PathVariable String id) {
      return new ResponseEntity&lt;&gt;(Result.Success("Hi " + id + "!!!", null), HttpStatus.OK);
  }
  </code></pre>
  
  <p>However, when I add an <code>@ModelAttribute</code> variable, I get 400 (Bad Request) as the http response code:</p>
  
  <pre><code>@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
  public ResponseEntity&lt;Result&gt; deleteTest(@PathVariable String id, @ModelAttribute("authUser") User authUser) {
      return new ResponseEntity&lt;&gt;(Result.Success("Hi " + id + "!!!", null), HttpStatus.OK);
  }
  </code></pre>
  
  <p>This <code>@ModelAttribute</code> is working fine with a put request handler I have in my <code>@RestController</code> but not in this delete request.</p>
  
  <p>Here's the <code>@ModelAttribute</code> code:</p>
  
  <pre><code>@ModelAttribute("authUser")
  public User authUser(@AuthenticationPrincipal SpringAuthUser springAuthUser) throws Exception {
      User user = ConstantsHome.userprofileMgr.getUserByUserId(springAuthUser.getUsername(), true, true);
      user.updateRights(null);
      request.getSession().setAttribute(ConstantsHome.USEROBJECT_KEY, user);
      return user;
  }
  </code></pre>
  
  <p>Why would adding <code>@ModelAttribute</code> cause a delete request to return a 400 (Bad Request) http response?</p>
  
  <p>I'm using spring-web-4.1.4 &amp; spring-security-4.0.3</p>