From f4febf2a15ca48dc0e98bef890840ae74989cf35 Mon Sep 17 00:00:00 2001
From: siwa-tkapplmueller
 <47564597+siwa-tkapplmueller@users.noreply.github.com>
Date: Mon, 19 Jul 2021 14:13:42 +0200
Subject: [PATCH 1/2] Fix exception when oldProperty is null

Fixes an exception that occurs when one property is null and the other is a DateTime object.
---
 Classes/Utility/UserUtility.php | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Classes/Utility/UserUtility.php b/Classes/Utility/UserUtility.php
index 3160e1351c..841cd256a1 100644
--- a/Classes/Utility/UserUtility.php
+++ b/Classes/Utility/UserUtility.php
@@ -246,18 +246,22 @@ public static function getDirtyPropertiesFromUser(User $changedObject)
                 && !in_array($propertyName, $ignoreProperties)
             ) {
                 $newPropertyValue = $changedObject->{'get' . ucfirst($propertyName)}();
-                if (!is_object($oldPropertyValue) || !is_object($newPropertyValue)) {
+                if (!is_object($oldPropertyValue) && !is_object($newPropertyValue)) {
                     if ($oldPropertyValue !== $newPropertyValue) {
                         $dirtyProperties[$propertyName]['old'] = $oldPropertyValue;
                         $dirtyProperties[$propertyName]['new'] = $newPropertyValue;
                     }
                 } else {
-                    if (get_class($oldPropertyValue) === 'DateTime') {
+                    if (($oldPropertyValue != null && get_class($oldPropertyValue) === 'DateTime') || ($newPropertyValue != null && get_class($newPropertyValue) === 'DateTime')) {
                         /** @var $oldPropertyValue \DateTime */
                         /** @var $newPropertyValue \DateTime */
-                        if ($oldPropertyValue->getTimestamp() !== $newPropertyValue->getTimestamp()) {
-                            $dirtyProperties[$propertyName]['old'] = $oldPropertyValue->getTimestamp();
-                            $dirtyProperties[$propertyName]['new'] = $newPropertyValue->getTimestamp();
+
+                        $oldTimestamp = $oldPropertyValue != null ? $oldPropertyValue->getTimestamp() : 0;
+                        $newTimestamp = $newPropertyValue != null ? $newPropertyValue->getTimestamp() : 0;
+
+                        if ($oldTimestamp !== $newTimestamp) {
+                            $dirtyProperties[$propertyName]['old'] = $oldTimestamp;
+                            $dirtyProperties[$propertyName]['new'] = $newTimestamp;
                         }
                     } else {
                         $titlesOld = ObjectUtility::implodeObjectStorageOnProperty($oldPropertyValue);

From baf2cb042420f0aa5266d281a1f04e9401c21a98 Mon Sep 17 00:00:00 2001
From: siwa-tkapplmueller
 <47564597+siwa-tkapplmueller@users.noreply.github.com>
Date: Mon, 19 Jul 2021 15:15:03 +0200
Subject: [PATCH 2/2] use type safe comparisons,  use instanceof instead of
 get_class

---
 Classes/Utility/UserUtility.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Classes/Utility/UserUtility.php b/Classes/Utility/UserUtility.php
index 841cd256a1..df5458d4be 100644
--- a/Classes/Utility/UserUtility.php
+++ b/Classes/Utility/UserUtility.php
@@ -252,12 +252,12 @@ public static function getDirtyPropertiesFromUser(User $changedObject)
                         $dirtyProperties[$propertyName]['new'] = $newPropertyValue;
                     }
                 } else {
-                    if (($oldPropertyValue != null && get_class($oldPropertyValue) === 'DateTime') || ($newPropertyValue != null && get_class($newPropertyValue) === 'DateTime')) {
+                    if (($oldPropertyValue !== null && $oldPropertyValue instanceof \DateTime) || ($newPropertyValue !== null && $newPropertyValue instanceof \DateTime)) {
                         /** @var $oldPropertyValue \DateTime */
                         /** @var $newPropertyValue \DateTime */
 
-                        $oldTimestamp = $oldPropertyValue != null ? $oldPropertyValue->getTimestamp() : 0;
-                        $newTimestamp = $newPropertyValue != null ? $newPropertyValue->getTimestamp() : 0;
+                        $oldTimestamp = $oldPropertyValue !== null ? $oldPropertyValue->getTimestamp() : 0;
+                        $newTimestamp = $newPropertyValue !== null ? $newPropertyValue->getTimestamp() : 0;
 
                         if ($oldTimestamp !== $newTimestamp) {
                             $dirtyProperties[$propertyName]['old'] = $oldTimestamp;