From 611b2997ab768b6b97ff825bd030efd4a2fafaf5 Mon Sep 17 00:00:00 2001
From: Matt Kane <m@mk.gg>
Date: Mon, 25 Oct 2021 19:18:41 +0100
Subject: [PATCH] fix: ensure stale-while-revalidate headers are not sent

---
 src/templates/getHandler.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/templates/getHandler.js b/src/templates/getHandler.js
index 84e3ead9c5..34d8cd0b8e 100644
--- a/src/templates/getHandler.js
+++ b/src/templates/getHandler.js
@@ -136,6 +136,11 @@ const makeHandler =
         multiValueHeaders['cache-control'] = ['no-cache']
       }
 
+      // Sending SWR headers causes undefined behaviour with the Netlify CDN
+      if (multiValueHeaders['cache-control']?.[0]?.includes('stale-while-revalidate')) {
+        multiValueHeaders['cache-control'] = ['public, max-age=0, must-revalidate']
+      }
+
       return {
         ...result,
         multiValueHeaders,