fixed previous merge and added some unit tests

CHANGELOG

@@ -1,3 +1,7 @@
+* 1.4.0-RC2
+
+ * added negative timestamp support to the date filter
+
 * 1.4.0-RC1 (2011-11-20)
 
  * optimized variable access when using PHP 5.4

lib/Twig/Extension/Core.php

@@ -237,11 +237,8 @@ function twig_cycle($values, $i)
 function twig_date_format_filter($date, $format = 'F j, Y H:i', $timezone = null)
 {
     if (!$date instanceof DateTime && !$date instanceof DateInterval) {
-        if (ctype_digit((string) $date)
-            || (!empty($date)
-                && ('-' === $date[0])
-                && ctype_digit(substr($date, 1)))
-        ) {
+        $asString = (string) $date;
+        if (ctype_digit($asString) || (!empty($asString) && '-' === $asString[0] && ctype_digit(substr($asString, 1)))) {
             $date = new DateTime('@'.$date);
             $date->setTimezone(new DateTimeZone(date_default_timezone_get()));
         } else {

test/Twig/Tests/Fixtures/filters/date.test

@@ -9,9 +9,17 @@
 {{ date3|date('d/m/Y') }}
 {{ date4|date }}
 {{ date4|date('d/m/Y') }}
+{{ date5|date }}
+{{ date5|date('d/m/Y') }}
 --DATA--
 date_default_timezone_set('UTC');
-return array('date1' => mktime(13, 45, 0, 10, 4, 2010), 'date2' => new DateTime('2010-10-04 13:45'), 'date3' => '2010-10-04 13:45', 'date4' => 1286199900)
+return array(
+    'date1' => mktime(13, 45, 0, 10, 4, 2010),
+    'date2' => new DateTime('2010-10-04 13:45'),
+    'date3' => '2010-10-04 13:45',
+    'date4' => 1286199900,
+    'date5' => -86410,
+)
 --EXPECT--
 October 4, 2010 13:45
 04/10/2010
@@ -21,3 +29,5 @@ October 4, 2010 13:45
 04/10/2010
 October 4, 2010 13:45
 04/10/2010
+December 30, 1969 23:59
+30/12/1969