[BUGFIX] Prevent PHP errors in FileMount model

This prevents an error triggered by accessing a possible
uninitialized property as well as a possible TypeError in
the newly introduced FileMount model.

Resolves: #99254
Related: #99038
Releases: main
Change-Id: I037ebd1322838f223ed19171b57118d039488936
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76888


Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>

typo3/sysext/beuser/Classes/Domain/Model/FileMount.php

@@ -38,7 +38,7 @@ class FileMount extends AbstractEntity
     /**
      * Description of the file mount.
      */
-    protected string $description;
+    protected string $description = '';
 
     /**
      * Identifier of the filemount
@@ -128,11 +128,13 @@ class FileMount extends AbstractEntity
      */
     public function getPath(): string
     {
-        $segments = preg_split('#:/#', $this->identifier);
-        return $segments[1] ?? '';
+        return explode(':/', $this->identifier)[1] ?? '';
     }
 
-    public function getStorage(): ResourceStorage
+    /**
+     * @todo This should be part of the ORM not the model class
+     */
+    public function getStorage(): ?ResourceStorage
     {
         return GeneralUtility::makeInstance(StorageRepository::class)->findByCombinedIdentifier($this->identifier);
     }