[BUGFIX] Prevent reset of user settings in getFromDottedNotation()

Change-Id: Idd9bd02e81ffb5b3ed02f5bf47d6fa3a9be7cdbd
Resolves: #76406
Releases: master, 7.6
Reviewed-on: https://review.typo3.org/48426


Reviewed-by: Markus Blaschke <typo3@schattenjaeger.net>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>

typo3/sysext/backend/Classes/Controller/UserSettingsController.php

@@ -202,10 +202,10 @@ class UserSettingsController
     protected function getFromDottedNotation($key)
     {
         $subkeys = GeneralUtility::trimExplode('.', $key);
-        $array = &$this->getBackendUser()->uc;
+        $array = $this->getBackendUser()->uc;
         foreach ($subkeys as $subkey) {
             if (isset($array[$subkey])) {
-                $array =  &$array[$subkey];
+                $array = &$array[$subkey];
             } else {
                 $array = [];
                 break;