Link to the code that reproduces this issue

https://github.com/ben-aggus-gateway/middlewarebug.git

To Reproduce

1. Run the application locally. Since this is middleware, it logs the nexturl object to the console.
2. In the local browser for the site, add a filepath that mimics a /_next/data path. This is a working example: http://localhost:3000/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json
3. Observe the console output. The 'href' key will show the mangled output. (path repeats, ends with .json.json) This is the result of the URL above:
   rewrite {
   href: 'https://www.mydomain.com/_next/data/TN22pxNPSlmN59JSJ1pFb/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json.json',
   origin: 'https://www.mydomain.com',
   protocol: 'https:',
   username: '',
   password: '',
   host: 'www.mydomain.com',
   hostname: 'www.mydomain.com',
   port: '',
   pathname: '/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json',
   search: '',
   searchParams: URLSearchParams {
   [Symbol(query)]: [],
   [Symbol(context)]: URL {
   [Symbol(context)]: URLContext {
   href: 'https://www.mydomain.com/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json',
   protocol_end: 6,
   username_end: 8,
   host_start: 8,
   host_end: 28,
   pathname_start: 28,
   search_start: 4294967295,
   hash_start: 4294967295,
   port: 4294967295,
   scheme_type: 2
   }
   }
   },
   hash: ''
   }

Providing "normal" URLs like /test/path will not produce the issue.

I have enabled skipMiddlewareUrlNormalize: true, in nextjs.config

Current vs. Expected behavior

Current behavior:
nexturl.href= https://www.mydomain.com/_next/data/TN22pxNPSlmN59JSJ1pFb/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json.json

(the path seems to repeat twice)

Expected behavior:
nexturl.href should = https://www.mydomain.com/_next/data/TN22pxNPSlmN59JSJ1pFb/support/security.json when that path is provided to the redirector (and a host has been provided like our case)

This code currently works in our production Next 13.4.19 environment and produces the expected behavior.

Verify canary release

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

Provide environment information

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 10 Enterprise
Binaries:
  Node: 18.18.2
  npm: N/A
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 14.0.3-canary.2
  eslint-config-next: N/A
  react: 18.2.0
  react-dom: 18.2.0
  typescript: 5.1.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Middleware / Edge (API routes, runtime)

Additional context

We are running 2 next sites. The need to rewrite /_next/data URLs is due to rewriting pages from 1 site to the other for certain pages.