title: Laravel redirect back not passing variable
body: <p>I am creating a simple page to hash strings with md5, however the output is never returned.</p>
  
  <p>This is the controller I use for these pages.
  The function md5 is routed to the get and the function md5post is routed to the post.
  The view has a form that is posted to the md5post function. it has one variable $input with the string to hash.</p>
  
  <pre><code>&lt;?php
  
  class ConversionsController extends \BaseController {
  
      private $withmd5;
  
      public function __construct(){
          $this-&gt;withmd5 = [
              'pagetitle' =&gt; 'MD5 hashing',
              'description' =&gt; 'description',
              'infoWindow' =&gt; 'info',
              'btnSumbit' =&gt; Form::submit('Hash', ['class' =&gt; 'btn btn-default'])
          ];
      }
  
  
      public function md5(){
          return View::make("layout.textareamaster")-&gt;with($this-&gt;withmd5);
      }
      public function md5post(){
  
          if (strlen(Input::get("input")) &gt; 0)
          {
              $hash = md5(Input::get("input"));
          }
  
          return Redirect::back()-&gt;withInput()-&gt;with("output", $hash);
      }
  
  }
  </code></pre>
  
  <p>And this is the view</p>
  
  <pre><code>{{ Form::open(['method' =&gt; 'post']) }}
      &lt;div class="row"&gt;
          &lt;div class="col-md-6"&gt;
              &lt;p class="well"&gt;
                  {{ Form::textarea('input', '', ['class' =&gt; 'form-control', 'rows' =&gt; 5]) }}
                  &lt;span style="float:right;"&gt;
                      {{ $btnSubmit or Form::submit('Go', ['class' =&gt; 'btn btn-default']) }}
                  &lt;/span&gt;
              &lt;/p&gt;
          &lt;/div&gt;
          &lt;div class="col-md-6"&gt;
              &lt;p class="well"&gt;
                  &lt;textarea class="form-control" rows="5" readonly="true"&gt;{{ $output or "nothing" }}&lt;/textarea&gt;
              &lt;/p&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  {{ Form::close() }}
  </code></pre>
  
  <p>When in my template file, the input is always displayed, however, the variable $output is always undefined. I have beent trying to use other variable names, but it wont work. </p>
  
  <p>If I return the variable right before the redirect, I see the correct output.</p>