i18n routing with rewrite on /[defaultLocale] next.config.js + middleware cased redirect loop

[williamli]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

npx --no-install next info [80%]

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 21.6.0: Mon Aug 22 20:19:52 PDT 2022; root:xnu-8020.140.49~2/RELEASE_ARM64_T6000
Binaries:
  Node: 16.17.0
  npm: 8.19.1
  Yarn: 1.22.19
  pnpm: N/A
Relevant packages:
  next: 12.3.0
  eslint-config-next: N/A
  react: 18.2.0
  react-dom: 18.2.0

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

Describe the Bug

Reproduction: https://github.com/vercel-support/93483-mre

next.config.js:

module.exports = {
  i18n: {
    defaultLocale: 'default',
    localeDetection: false,
    locales: ['default', 'en-gb', 'en-ca'],
  },
  async rewrites() {
    return [
      {
        destination: '/en-gb/nextjs.org',
        source: '/default',
        locale: false,
      },
      {
        destination: '/en-ca/nextjs.org',
        source: '/en-ca',
        locale: false,
      },
    ];
  },
};

middleware.js:

import { NextResponse } from 'next/server';

export function middleware() {
  return NextResponse.next();
}

When you visit /, you will enter a redirect loop.

If middleware.js or the rewrite on /default is removed, then there will not be a redirect loop.

Expected Behavior

Request for / should not result in a redirect loop.

Link to reproduction

https://github.com/vercel-support/93483-mre

To Reproduce

Reproduction: https://github.com/vercel-support/93483-mre

next.config.js:

module.exports = {
  i18n: {
    defaultLocale: 'default',
    localeDetection: false,
    locales: ['default', 'en-gb', 'en-ca'],
  },
  async rewrites() {
    return [
      {
        destination: '/en-gb/nextjs.org',
        source: '/default',
        locale: false,
      },
      {
        destination: '/en-ca/nextjs.org',
        source: '/en-ca',
        locale: false,
      },
    ];
  },
};

middleware.js:

import { NextResponse } from 'next/server';

export function middleware() {
  return NextResponse.next();
}

When you visit /, you will enter a redirect loop.

[vercel-release-bot]

This issue has been automatically marked as stale due to two years of inactivity. It will be closed in 7 days unless there’s further input. If you believe this issue is still relevant, please leave a comment or provide updated details. Thank you.