bug symfony#28466 [Form] fail reverse transforming invalid RFC 3339 dates (xabbuh)

This PR was merged into the 2.8 branch.

Discussion
----------

[Form] fail reverse transforming invalid RFC 3339 dates

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#28455
| License       | MIT
| Doc PR        |

Commits
-------

ee4ce43 fail reverse transforming invalid RFC 3339 dates

Author: nicolas-grekas

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToRfc3339Transformer.php

@@ -69,6 +69,10 @@ public function reverseTransform($rfc3339)
             return;
         }
 
+        if (!preg_match('/^(\d{4})-(\d{2})-(\d{2})T\d{2}:\d{2}(?::\d{2})?(?:\.\d)?(?:Z|(?:(?:\+|-)\d{2}:\d{2}))$/', $rfc3339, $matches)) {
+            throw new TransformationFailedException(sprintf('The date "%s" is not a valid date.', $rfc3339));
+        }
+
         try {
             $dateTime = new \DateTime($rfc3339);
         } catch (\Exception $e) {
@@ -79,10 +83,8 @@ public function reverseTransform($rfc3339)
             $dateTime->setTimezone(new \DateTimeZone($this->inputTimezone));
         }
 
-        if (preg_match('/(\d{4})-(\d{2})-(\d{2})/', $rfc3339, $matches)) {
-            if (!checkdate($matches[2], $matches[3], $matches[1])) {
-                throw new TransformationFailedException(sprintf('The date "%s-%s-%s" is not a valid date.', $matches[1], $matches[2], $matches[3]));
-            }
+        if (!checkdate($matches[2], $matches[3], $matches[1])) {
+            throw new TransformationFailedException(sprintf('The date "%s-%s-%s" is not a valid date.', $matches[1], $matches[2], $matches[3]));
         }
 
         return $dateTime;

src/Symfony/Component/Form/Tests/Extension/Core/DataTransformer/DateTimeToRfc3339TransformerTest.php

@@ -134,12 +134,25 @@ public function testReverseTransformWithNonExistingDate()
     }
 
     /**
+     * @dataProvider invalidDateStringProvider
      * @expectedException \Symfony\Component\Form\Exception\TransformationFailedException
      */
-    public function testReverseTransformExpectsValidDateString()
+    public function testReverseTransformExpectsValidDateString($date)
     {
         $transformer = new DateTimeToRfc3339Transformer('UTC', 'UTC');
 
-        $transformer->reverseTransform('2010-2010-2010');
+        $transformer->reverseTransform($date);
+    }
+
+    public function invalidDateStringProvider()
+    {
+        return array(
+            'invalid month' => array('2010-2010-01'),
+            'invalid day' => array('2010-10-2010'),
+            'no date' => array('x'),
+            'cookie format' => array('Saturday, 01-May-2010 04:05:00 Z'),
+            'RFC 822 format' => array('Sat, 01 May 10 04:05:00 +0000'),
+            'RSS format' => array('Sat, 01 May 2010 04:05:00 +0000'),
+        );
     }
 }