From c034838c71d20a3e7d0b4d4345586887e8db2962 Mon Sep 17 00:00:00 2001
From: Steve <steve@silverstripe.com>
Date: Wed, 30 Nov 2016 14:49:03 +1300
Subject: [PATCH] Update Versioned.php

Change isset() to array_key_exists(). In the CMS, if you have a FormField such as 'My value', then you change it to '' (blank), isset() will return false because even though the key exists, the value === null by the time it reaches this point in the code, and isset() return false on null values. array_key_exists will return true with a null value
---
 model/Versioned.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/model/Versioned.php b/model/Versioned.php
index 6ab3a25a4..c84e2b6a4 100644
--- a/model/Versioned.php
+++ b/model/Versioned.php
@@ -607,7 +607,7 @@ class Versioned extends DataExtension implements TemplateGlobalProvider {
 				$data = array_intersect_key($data, $fields);
 
 				foreach ($data as $k => $v) {
-					if (!isset($newManipulation['fields'][$k])) {
+					if (!array_key_exists($k, $newManipulation['fields'])) {
 						$newManipulation['fields'][$k] = $v;
 					}
 				}