[BUGFIX] Make tstemplate respect hidden flags for sys_template records

Previously, the tstemplate Object Browser would wrongly show hidden
typoscript templates, if they were the first one to be found
(which determined by the sorting key).
The hidden flag will now only be ignored, if a hidden template is
explicitly requested by its uid (using the template selector switch).

Resolves: #88507
Releases: main, 11.5
Change-Id: Ibbfeb2de7f8ee79a1e343ff23f9d1064219eb344
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63516
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>

typo3/sysext/tstemplate/Classes/Controller/TypoScriptTemplateObjectBrowserModuleFunctionController.php

@@ -19,6 +19,8 @@
 use TYPO3\CMS\Backend\Routing\UriBuilder;
 use TYPO3\CMS\Backend\Utility\BackendUtility;
 use TYPO3\CMS\Core\Authentication\BackendUserAuthentication;
+use TYPO3\CMS\Core\Context\Context;
+use TYPO3\CMS\Core\Context\VisibilityAspect;
 use TYPO3\CMS\Core\DataHandling\DataHandler;
 use TYPO3\CMS\Core\Exception;
 use TYPO3\CMS\Core\Localization\LanguageService;
@@ -143,15 +145,21 @@ protected function initialize_editor($pageId, $template_uid = 0)
         // Defined global here!
         $this->templateService = GeneralUtility::makeInstance(ExtendedTemplateService::class);
 
+        $this->templateRow = $this->templateService->ext_getFirstTemplate($pageId, $template_uid);
+        $hasFirstTemplate = is_array($this->templateRow);
+        // No explicitly selected template on this page was found, so we behave like the Frontend (e.g. when a template is hidden but on the page above)
+        if (!$hasFirstTemplate) {
+            // Re-initiatlize the templateService but do not include hidden templates
+            $context = clone GeneralUtility::makeInstance(Context::class);
+            $context->setAspect('visibility', GeneralUtility::makeInstance(VisibilityAspect::class));
+            $this->templateService = GeneralUtility::makeInstance(ExtendedTemplateService::class, $context);
+        }
         // Gets the rootLine
         $rootlineUtility = GeneralUtility::makeInstance(RootlineUtility::class, $pageId);
         $rootLine = $rootlineUtility->get();
         // This generates the constants/config + hierarchy info for the template.
         $this->templateService->runThroughTemplates($rootLine, $template_uid);
-
-        // Get the row of the first VISIBLE template of the page. whereclause like the frontend.
-        $this->templateRow = $this->templateService->ext_getFirstTemplate($pageId, $template_uid);
-        return is_array($this->templateRow);
+        return $hasFirstTemplate;
     }
 
     /**