[Form] Disallow transform dates beyond the year 9999

Author: curry684

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

@@ -123,6 +123,9 @@ public function reverseTransform($value)
 
         if (0 != intl_get_error_code()) {
             throw new TransformationFailedException(intl_get_error_message());
+        } elseif ($timestamp > 253402214400) {
+            // This timestamp represents UTC midnight of 9999-12-31 to prevent 5+ digit years
+            throw new TransformationFailedException('Years beyond 9999 are not supported.');
         }
 
         try {

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

@@ -343,4 +343,22 @@ public function testReverseTransformOutOfTimestampRange()
         $transformer = new DateTimeToLocalizedStringTransformer('UTC', 'UTC');
         $transformer->reverseTransform('1789-07-14');
     }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function testReverseTransformFiveDigitYears()
+    {
+        $transformer = new DateTimeToLocalizedStringTransformer('UTC', 'UTC', null, null, \IntlDateFormatter::GREGORIAN, 'yyyy-MM-dd');
+        $transformer->reverseTransform('20107-03-21');
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function testReverseTransformFiveDigitYearsWithTimestamp()
+    {
+        $transformer = new DateTimeToLocalizedStringTransformer('UTC', 'UTC', null, null, \IntlDateFormatter::GREGORIAN, 'yyyy-MM-dd HH:mm:ss');
+        $transformer->reverseTransform('20107-03-21 12:34:56');
+    }
 }