[BUGFIX] Fix exception in view module for missing site configuration

When opening a page in the view module, that belongs to a page
tree with no valid site configuration, an exception was thrown,
because the ModuleData clean-method was expecting at least one
item in the language array.

Resolves: #100092
Releases: main
Change-Id: I60ae316e29ec87d62ba8728103283bbe0778f0c8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78032


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>

typo3/sysext/viewpage/Classes/Controller/ViewModuleController.php

@@ -81,7 +81,8 @@ class ViewModuleController
             return $view->renderResponse('Empty');
         }
 
-        if ($moduleData->clean('language', array_keys($this->getPreviewLanguages($pageId)))) {
+        $previewLanguages = $this->getPreviewLanguages($pageId);
+        if ($previewLanguages !== [] && $moduleData->clean('language', array_keys($previewLanguages))) {
             $this->getBackendUser()->pushModuleData($moduleData->getModuleIdentifier(), $moduleData->toArray());
         }
         $languageId = (int)$moduleData->get('language');