[🐛 Bug]: Can't set headers in middleware when receiving request with "RCS: 1"

[SamyPesse]

next-on-pages environment related information

System:
Platform: darwin
Arch: arm64
Version: Darwin Kernel Version 24.0.0: Tue Sep 24 23:39:07 PDT 2024; root:xnu-11215.1.12~1/RELEASE_ARM64_T6000
CPU: (10) arm64 Apple M1 Pro
Memory: 16 GB
Shell: /bin/zsh
Package Manager Used: bun (1.1.30)

Relevant Packages:
@cloudflare/next-on-pages: 1.13.5
vercel: N/A
next: N/A

Description

I'm still trying to deep dive into the code of next-on-pages to understand, but it's reproducible when deploying to Cloudflare Pages, but working fine locally with next dev:

In a middleware, when setting headers on the response after a NextResponse.rewrite, these headers are never sent to the end response.

Reproduction

(I'll provide a reproduction asap but wanted to see if people had idea on workaround first)

With middleware that contains:

const response = NextResponse.rewrite(target);
response.headers.set('x-helloworld', 'hello');

return response;

When doing the request GET /, you get the header x-helloworld.

But if you do the request as a router transition/prefetch (reproducible by passing the header RCS: 1), you don't get the header.

Pages Deployment Method

Direct Upload (wrangler pages publish or the @cloudflare/pages-action GitHub Action)

Pages Deployment ID

dd6d6274-8152-412a-8199-18bb44004a0f

Additional Information

No response

Would you like to help?

• Would you like to help fixing this bug?