Merge pull request #60024 from nextcloud/backport/59952/stable32

[stable32] fix(core): provide valid initial state also on public templates

Author: susnux

lib/private/TemplateLayout.php

@@ -156,7 +156,8 @@ public function getPageTemplate(string $renderAs, string $appId): ITemplate {
 				$page->assign('appid', $appId);
 				$page->assign('bodyid', 'body-public');
 
-				$this->initialState->provideInitialState('core', 'apps', [$this->navigationManager->get($appId)]);
+				$currentAppData = $this->navigationManager->get($appId);
+				$this->initialState->provideInitialState('core', 'apps', $currentAppData === null ? [] : [$currentAppData]);
 
 				// Set logo link target
 				$logoUrl = $this->config->getSystemValueString('logo_url', '');