title: Laravel's withInput() and withErrors() are empty
body: <p>I have a laravel form which submits data via a POST request to a controller like so...</p>
  
  <pre><code>public function store()
  {
      $result = Validator::make(request() -&gt; all(), $this -&gt; rules);
  
      if ($result -&gt; fails()) 
      { 
          return back() -&gt; withInput() -&gt; withErrors($result); 
      }
  }
  </code></pre>
  
  <p>However, when I'm redirected back, accessing input data via the 'old' helper method returns nothing, as does reading data from $errors. </p>
  
  <p>I believe the session data is being lost (possibly due to a secondary redirect?).</p>
  
  <p>I've checked my routes file in artisan and the web middleware is only being run once on the routes. I'm also using the database session driver.</p>
  
  <p>Any ideas? I'm using Laravel 5.2.39</p>