From 779bb9e06ae5e9fcea3c52c1f3bad38990b3850b Mon Sep 17 00:00:00 2001
From: Alex Kirszenberg <alex.kirszenberg@vercel.com>
Date: Tue, 31 Jan 2023 17:43:01 +0100
Subject: [PATCH] Return a 404 status code when a data route is `.notFound`
 (vercel/turbo#3545)

Returning a 404 status code is required for the client-side router to
redirect to the error page.
---
 .../crates/next-core/js/src/internal/page-server-handler.tsx  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/next-swc/crates/next-core/js/src/internal/page-server-handler.tsx b/packages/next-swc/crates/next-core/js/src/internal/page-server-handler.tsx
index f7b880db00..31b24328d9 100644
--- a/packages/next-swc/crates/next-core/js/src/internal/page-server-handler.tsx
+++ b/packages/next-swc/crates/next-core/js/src/internal/page-server-handler.tsx
@@ -206,7 +206,9 @@ export default function startHandler({
       if (isDataReq) {
         return {
           type: "response",
-          statusCode,
+          // Returning a 404 status code is required for the client-side router
+          // to redirect to the error page.
+          statusCode: 404,
           body: '{"notFound":true}',
           headers: [["Content-Type", MIME_APPLICATION_JAVASCRIPT]],
         };