bug #23254 [Form][TwigBridge] render hidden _method field in form_rest() (xabbuh)

This PR was merged into the 2.7 branch.

Discussion
----------

[Form][TwigBridge] render hidden _method field in form_rest()

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #14261
| License       | MIT
| Doc PR        |

Commits
-------

0ee3f57533 render hidden _method field in form_rest()

src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig

@@ -262,6 +262,7 @@
 {%- endblock form -%}
 
 {%- block form_start -%}
+    {%- do form.setMethodRendered() -%}
     {% set method = method|upper %}
     {%- if method in ["GET", "POST"] -%}
         {% set form_method = method %}
@@ -301,6 +302,20 @@
             {{- form_row(child) -}}
         {% endif %}
     {%- endfor %}
+
+    {% if not form.methodRendered %}
+        {%- do form.setMethodRendered() -%}
+        {% set method = method|upper %}
+        {%- if method in ["GET", "POST"] -%}
+            {% set form_method = method %}
+        {%- else -%}
+            {% set form_method = "POST" %}
+        {%- endif -%}
+
+        {%- if form_method != method -%}
+            <input type="hidden" name="_method" value="{{ method }}" />
+        {%- endif -%}
+    {% endif %}
 {% endblock form_rest %}
 
 {# Support #}

src/Symfony/Bridge/Twig/composer.json

@@ -22,7 +22,7 @@
     "require-dev": {
         "symfony/asset": "~2.7",
         "symfony/finder": "~2.3",
-        "symfony/form": "~2.7.26|^2.8.19",
+        "symfony/form": "~2.7.30|^2.8.23",
         "symfony/http-kernel": "~2.3",
         "symfony/intl": "~2.3",
         "symfony/routing": "~2.2",
@@ -36,6 +36,9 @@
         "symfony/var-dumper": "~2.7.16|^2.8.9",
         "symfony/expression-language": "~2.4"
     },
+    "conflict": {
+        "symfony/form": "<2.7.30|~2.8,<2.8.23"
+    },
     "suggest": {
         "symfony/finder": "",
         "symfony/asset": "For using the AssetExtension",

src/Symfony/Component/Form/FormView.php

@@ -53,6 +53,8 @@ class FormView implements \ArrayAccess, \IteratorAggregate, \Countable
      */
     private $rendered = false;
 
+    private $methodRendered = false;
+
     public function __construct(FormView $parent = null)
     {
         $this->parent = $parent;
@@ -90,6 +92,19 @@ class FormView implements \ArrayAccess, \IteratorAggregate, \Countable
         return $this;
     }
 
+    /**
+     * @return bool
+     */
+    public function isMethodRendered()
+    {
+        return $this->methodRendered;
+    }
+
+    public function setMethodRendered()
+    {
+        $this->methodRendered = true;
+    }
+
     /**
      * Returns a child by name (implements \ArrayAccess).
      *