Add correct method for hardcoded `/f/{fileid}`

Signed-off-by: Joas Schilling <coding@schilljs.com>

apps/files/lib/Controller/ViewController.php

@@ -128,6 +128,18 @@ class ViewController extends Controller {
 		return \OC_Helper::getStorageInfo('/', $dirInfo);
 	}
 
+	/**
+	 * @NoCSRFRequired
+	 * @NoAdminRequired
+	 *
+	 * @param string $fileid
+	 * @return TemplateResponse|RedirectResponse
+	 */
+	public function showFile(string $fileid = null): Response {
+		// This is the entry point from the `/f/{fileid}` URL which is hardcoded in the server.
+		return $this->redirectToFile($fileid);
+	}
+
 	/**
 	 * @NoCSRFRequired
 	 * @NoAdminRequired
@@ -140,7 +152,7 @@ class ViewController extends Controller {
 	public function index($dir = '', $view = '', $fileid = null, $fileNotFound = false) {
 		if ($fileid !== null) {
 			try {
-				return $this->showFile($fileid);
+				return $this->redirectToFile($fileid);
 			} catch (NotFoundException $e) {
 				return new RedirectResponse($this->urlGenerator->linkToRoute('files.view.index', ['fileNotFound' => true]));
 			}
@@ -285,7 +297,7 @@ class ViewController extends Controller {
 	 * @return RedirectResponse redirect response or not found response
 	 * @throws \OCP\Files\NotFoundException
 	 */
-	private function showFile($fileId) {
+	private function redirectToFile($fileId) {
 		$uid        = $this->userSession->getUser()->getUID();
 		$baseFolder = $this->rootFolder->getUserFolder($uid);
 		$files      = $baseFolder->getById($fileId);