title: validation of form embed
body: <p>I have a form using a collection of embed forms.</p>
  
  <p>In my main form, i have a validation on a field "comment". This validation, simple, works fine.
  My collection of embed form treat another entity. I would like to have a validation on this entity field               </p>
  
  <pre><code>|  comment (min length = 5 ok) ------
                                      |   anotherfield (min length = 5 not ok)    
                                      |   anotherfield (min length = 5 not ok) 
  </code></pre>
  
  <p>I call the two form validations rules by the validation.yml file:</p>
  
  <pre><code>My\Bundle\Entity\Main:
      properties:
          comment:
              - Length: 
                  min: 5
                  minMessage: "minmessage"
  
  My\Bundle\Entity\EmbedEntity:
      properties:
          anotherfield:
              - Length: 
                  min: 5
                  minMessage: "minmessage"
  </code></pre>
  
  <p>But the second validation is just ignored and my form is commited. (no errors returned and go through <code>$form is-&gt;valid()</code> )</p>
  
  <p>My validation file is read. (my first validation on comment is fine)</p>
  
  <p>Am I missing something?</p>