form rendering bug

gistfile1.twig

<!-- no extends -->

{% use 'form_div_layout.html.twig' with widget_attributes as base_widget_attributes %}
{% block widget_attributes %}
    {% set full_name = name %}
    {{ block('base_widget_attributes') }}
{% endblock widget_attributes %}

{% form_theme form _self %}

<!-- faulty block prints this -->
id="" name=""
<!-- end block prints -->

<!-- correct form rendering here -->

solved with:

{% block widget_attributes %}
{% spaceless %}
{% if id is not empty %}id="{{ id }}" {% endif %} {% if name is not empty %}name="{{ name }}" {% endif %} {% if read_only %} readonly="readonly"{% endif %}{% if disabled %} disabled="disabled"{% endif %}{% if required %} required="required"{% endif %}{% if max_length %} maxlength="{{ max_length }}"{% endif %}{% if pattern %} pattern="{{ pattern }}"{% endif %}
{% for attrname, attrvalue in attr %}{% if attrname in ['placeholder', 'title'] %}{{ attrname }}="{{ attrvalue|trans({}, translation_domain) }}" {% else %}{{ attrname }}="{{ attrvalue }}" {% endif %}{% endfor %}
{% endspaceless %}
{% endblock widget_attributes %}

will submit a patch