title: "Default" validation group not transformed into group sequence in embedded entity
body: <p>I have the following form type:</p>
  
  <pre><code>class ProjectStep1Type extends AbstractType
  {
      public function buildForm(FormBuilderInterface $builder, array $options)
      {
          $builder-&gt;add('client', new ClientType(), [
              'label' =&gt; 'Client',
          ]);
  
          // More fields
  
          // Save as draft button
          $builder-&gt;add('saveDraft', 'submit', [
              'label' =&gt; 'Save as draft',
          ]);
          // Actual submit button
          $builder-&gt;add('validate', 'submit', [
              'label' =&gt; 'Validate',
          ]);
      }
  
      public function configureOptions(OptionsResolver $resolver)
      {
          $validationGroups = function(FormInterface $form) {
              if ($form-&gt;get('saveDraft')-&gt;isClicked()) {
  
                  return ['Default', 'Draft'];
              }
  
              return ['Default', 'Step1'];
          };
  
          $resolver-&gt;setDefaults([
              'data_class'        =&gt; 'AppBundle\Entity\Project',
              'validation_groups' =&gt; $validationGroups,
          ]);
      }
  }
  </code></pre>
  
  <p>The (partial) validation yaml file looks like this:</p>
  
  <pre><code>AppBundle\Entity\Client:
      group_sequence:
          - Client
          - TypesOK
      properties:
          label:
              - NotNull:
                  groups: [Step1]
              - Type: string
              - Length:
                  max: 255
                  groups: [TypesOK]
          vatCode:
              - NotNull:
                  groups: [Step1]
              - Type:
                  type: string
          contact:
              - NotNull: ~
              - Type: AppBundle\Entity\Contact
              - Valid: ~
          address:
              - Type: AppBundle\Entity\Address
              - Valid: ~
          sector:
              - NotNull:
                  groups: [Step1]
              - Type: AppBundle\Entity\CompanySector
  
  AppBundle\Entity\Project:
      group_sequence:
          - Project
          - TypesOK
      properties:
          client:
              - NotNull:
                  message: form.project.client.error.not_null
              - Type: AppBundle\Entity\Client
              - Valid: ~
          status:
              - NotNull: ~
              - Type: string
              - Choice:
                  choices: [DRAFT_1, DRAFT_2, DRAFT_3, SENT, REJECTED, DELETED]
                  groups: [TypesOK]
  </code></pre>
  
  <p>Now on to the problem: When I validate the form, the <code>Project</code> entity is correctly validated, once for each group in the sequence, i.e. <code>[Project, TypesOK, Draft]</code>.</p>
  
  <p>The <code>Client</code> entity, however, is validated using the <code>Default</code> validation group. If the validation succeeds with <code>Default</code>, the groups <code>Client</code> and <code>TypesOK</code> are not called.</p>
  
  <p>If the validation fails however, these groups are called! And error messages I would rather not have at this point are displayed along with the errors raised when validated with <code>Default</code>.</p>
  
  <p>What I expected is that <code>Client</code> is never validated using <code>Default</code>, but that, instead, the <code>Default</code> group be converted to the group sequence <code>[Client, TypesOK]</code>, even if it goes through the <code>Valid</code> constraint.</p>
  
  <p>Am I missing something?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>I made some progression about this. The validation problem I have only happens when I edit the form. When I edit the form, a Proxy class inheriting <code>Client</code> is used instead of the regular <code>Client</code> class.</p>
  
  <p>A normal feature for Doctrine.</p>
  
  <p>However, the validator metadata factory does not use the group sequence of the parent <code>Client</code>. It fetches its constraints, but not this property.</p>
  
  <p>It seems this problem is quite close to <a href="https://stackoverflow.com/questions/30008760/symfony-2-validate-proxy-entity">this other question</a> however the resolution in there do not work for me.</p>
  
  <p>The problem seems pretty clear for me now, however I have no idea about how I should solve this properly.</p>