bug #726 Use rootform test to check by root form view (yceruto)

This PR was merged into the master branch.

Discussion
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Use rootform test to check by root form view

This is consistent with the latest changes in the form themes and avoids any future collision between form view properties and form fields.

See symfony/symfony#25236

Commits
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bb11ddf Use rootform test to check by root form view

Author: javiereguiluz

templates/form/layout.html.twig

@@ -4,13 +4,13 @@
 
 {% block form_errors -%}
     {% if errors|length > 0 -%}
-        {% if form.parent %}<span class="help-block">{% else %}<div class="alert alert-danger">{% endif %}
+        {% if form is not rootform %}<span class="help-block">{% else %}<div class="alert alert-danger">{% endif %}
         <ul class="list-unstyled">
         {%- for error in errors -%}
             {# use font-awesome icon library #}
             <li><span class="fa fa-exclamation-triangle"></span> {{ error.message }}</li>
         {%- endfor -%}
         </ul>
-        {% if form.parent %}</span>{% else %}</div>{% endif %}
+        {% if form is not rootform %}</span>{% else %}</div>{% endif %}
     {%- endif %}
 {%- endblock form_errors %}