Fix 403 and 404 redirect

* Nextcloud is not properly loaded in the standalone version (especially the theming)
* it is already not listed anymore in the Nginx config (see nextcloud/documentation#392)
* the index.php-free version doesn't support this

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

core/templates/403.php

 <?php
 // @codeCoverageIgnoreStart
-if(!isset($_)) {//also provide standalone error page
+if(!isset($_)) {//standalone  page is not supported anymore - redirect to /
 	require_once '../../lib/base.php';
-	
-	$tmpl = new OC_Template( '', '403', 'guest' );
-	$tmpl->printPage();
+
+	$urlGenerator = \OC::$server->getURLGenerator();
+	header('Location: ' . $urlGenerator->getAbsoluteURL('/'));
 	exit;
 }
 // @codeCoverageIgnoreEnd

core/templates/404.php

@@ -3,11 +3,11 @@
 /** @var $l \OCP\IL10N */
 /** @var $theme OCP\Defaults */
 // @codeCoverageIgnoreStart
-if(!isset($_)) {//also provide standalone error page
+if(!isset($_)) {//standalone  page is not supported anymore - redirect to /
 	require_once '../../lib/base.php';
-	
-	$tmpl = new OC_Template( '', '404', 'guest' );
-	$tmpl->printPage();
+
+	$urlGenerator = \OC::$server->getURLGenerator();
+	header('Location: ' . $urlGenerator->getAbsoluteURL('/'));
 	exit;
 }
 // @codeCoverageIgnoreEnd

lib/private/Setup.php

@@ -449,10 +449,10 @@ class Setup {
 		$htaccessContent = explode($content, $htaccessContent, 2)[0];
 
 		//custom 403 error page
-		$content.= "\nErrorDocument 403 ".$webRoot."/core/templates/403.php";
+		$content.= "\nErrorDocument 403 ".$webRoot."/";
 
 		//custom 404 error page
-		$content.= "\nErrorDocument 404 ".$webRoot."/core/templates/404.php";
+		$content.= "\nErrorDocument 404 ".$webRoot."/";
 
 		// Add rewrite rules if the RewriteBase is configured
 		$rewriteBase = $config->getValue('htaccess.RewriteBase', '');

tests/Core/Templates/TemplatesTest.php

-<?php
-
-namespace Tests\Core\Templates;
-
-class TemplatesTest extends \Test\TestCase {
-
-	public function test403() {
-		$template = \OC::$SERVERROOT . '/core/templates/403.php';
-		$expectedHtml = "<ul><li class='error'>\n\t\tAccess forbidden<br><p class='hint'></p></li></ul>";
-		$this->assertTemplate($expectedHtml, $template);
-	}
-
-	public function test404() {
-		$template = \OC::$SERVERROOT . '/core/templates/404.php';
-		$href = \OC::$server->getURLGenerator()->linkTo('', 'index.php');
-		$expectedHtml = "<ul><li class='error'>\n\t\t\tFile not found<br><p class='hint'>The specified document has not been found on the server.</p>\n<p class='hint'><a href='$href'>You can click here to return to Nextcloud.</a></p>\n\t\t</li></ul>";
-		$this->assertTemplate($expectedHtml, $template);
-	}
-
-}