[BUGFIX] Force typecast to string in ArrayBrowser

Make sure that the key in ArrayBrowser::getSearchKeys() is always cast
to string.

Resolves: #91007
Releases: master
Change-Id: I28aa780a92f9425df486cb0dadee3930b4a54f14
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64124


Tested-by: Christian Eßl <indy.essl@gmail.com>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Jonas Eberle <flightvision@googlemail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Eßl <indy.essl@gmail.com>
Reviewed-by: Jonas Eberle <flightvision@googlemail.com>
Reviewed-by: Benni Mack <benni@typo3.org>

typo3/sysext/backend/Classes/View/ArrayBrowser.php

@@ -150,15 +150,15 @@ class ArrayBrowser
             $deeper = is_array($keyArr[$key]);
             if ($this->regexMode) {
                 if (
-                    is_scalar($keyArr[$key]) && preg_match('/' . $searchString . '/', $keyArr[$key])
-                    || $this->searchKeysToo && preg_match('/' . $searchString . '/', $key)
+                    is_scalar($keyArr[$key]) && preg_match('/' . $searchString . '/', (string)$keyArr[$key])
+                    || $this->searchKeysToo && preg_match('/' . $searchString . '/', (string)$key)
                 ) {
                     $this->searchKeys[$depth] = 1;
                 }
             } else {
                 if (
-                    is_scalar($keyArr[$key]) && stripos($keyArr[$key], $searchString) !== false
-                    || $this->searchKeysToo && stripos($key, $searchString) !== false
+                    is_scalar($keyArr[$key]) && stripos((string)$keyArr[$key], $searchString) !== false
+                    || $this->searchKeysToo && stripos((string)$key, $searchString) !== false
                 ) {
                     $this->searchKeys[$depth] = 1;
                 }