Fixed the Expires: 0 header

Author: ezimuel

src/Header/Expires.php

@@ -9,6 +9,9 @@
 
 namespace Zend\Http\Header;
 
+use DateTime;
+use DateTimeZone;
+
 /**
  * Expires Header
  *
@@ -25,4 +28,13 @@ public function getFieldName()
     {
         return 'Expires';
     }
+
+
+    public function setDate($date)
+    {
+        if ($date === '0') {
+            $date = date(DATE_W3C, 0); // Thu, 01 Jan 1970 00:00:00 GMT
+        }
+        return parent::setDate($date);
+    }
 }

test/Header/ExpiresTest.php

@@ -54,4 +54,14 @@ public function testPreventsCRLFAttackViaFromString()
     {
         $header = Expires::fromString("Expires: Sun, 06 Nov 1994 08:49:37 GMT\r\n\r\nevilContent");
     }
+
+    public function testExpiresSetToZero()
+    {
+        $expires = Expires::fromString("Expires: 0");
+        $this->assertEquals('Expires: Thu, 01 Jan 1970 00:00:00 GMT', $expires->toString());
+
+        $expires = new Expires();
+        $expires->setDate('0');
+        $this->assertEquals('Expires: Thu, 01 Jan 1970 00:00:00 GMT', $expires->toString());
+    }
 }