title: jbuilder view renders with layout
body: <p>I have a controller that sometimes renders html and sometimes json. </p>
  
  <p>For json I use jbuilder views.</p>
  
  <p>There is a default html layout, that for some unknown reason start to get rendered also for the json view.</p>
  
  <p>I found 2 options that fixes the issue</p>
  
  <ol>
  <li>add <code>layout:false</code> to the render call with the json view</li>
  <li>call render partial instead a regular render.</li>
  </ol>
  
  <p>I'm just wondering(cause it didn't rendered the layout a few days ago) 
  Is there a way to tell rails to render the layout only for html request formats ?  </p>