From 236f1b64f9dec26c98cdaf9efd66750001dc8da2 Mon Sep 17 00:00:00 2001
From: Joas Schilling <coding@schilljs.com>
Date: Fri, 30 Apr 2021 23:09:29 +0200
Subject: [PATCH] Reply with JSON when html is not accepted like in
 SecurityMiddleware

Signed-off-by: Joas Schilling <coding@schilljs.com>
---
 index.php | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/index.php b/index.php
index 6bdaf9d477..88104e1974 100644
--- a/index.php
+++ b/index.php
@@ -55,6 +55,18 @@ try {
 		OC_Template::printExceptionErrorPage($ex, 500);
 	}
 } catch (\OC\User\LoginException $ex) {
+	$request = \OC::$server->getRequest();
+	/**
+	 * Routes with the @CORS annotation and other API endpoints should
+	 * not return a webpage, so we only print the error page when html is accepted,
+	 * otherwise we reply with a JSON array like the SecurityMiddleware would do.
+	 */
+	if (stripos($request->getHeader('Accept'),'html') === false) {
+		http_response_code(401);
+		header('Content-Type: application/json; charset=utf-8');
+		echo json_encode(['message' => $ex->getMessage()]);
+		exit();
+	}
 	OC_Template::printErrorPage($ex->getMessage(), $ex->getMessage(), 401);
 } catch (Exception $ex) {
 	\OC::$server->getLogger()->logException($ex, ['app' => 'index']);