Disabling useFileSystemPublicRoutes prevents rendering of dynamic routes

Verify canary release

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

Provide environment information

    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: 16.15.1
      npm: 8.11.0
      Yarn: N/A
      pnpm: N/A
    Relevant packages:
      next: 12.3.1
      eslint-config-next: N/A
      react: 17.0.2
      react-dom: 17.0.2

What browser are you using? (if relevant)

Chrome, Safari

How are you deploying your application? (if relevant)

Custom Server

Describe the Bug

When I set useFileSystemPublicRoutes: false, dynamic routes are no longer handled by app.render and trigger a 404, even when I have an specific handler for this path.

Is worth to mention this issue only occurs on production build, the dev server works fine.

could this #33808 introduce the bug? this was introduced in next@12.1.0, previous versions of next works fine

Looks like this bug was alredy reported, but closed for inactivity #32004

Expected Behavior

App is able to resolve dynamic routes

Link to reproduction

To Reproduce

Run the follow code as production

next.config.js

module.exports = {
    useFileSystemPublicRoutes: false
};

server.js

'use strict';

const { createServer } = require('http')
const { parse } = require('url')
const next = require('next')

const dev = process.env.NODE_ENV !== 'production'
const hostname = 'localhost'
const port = 3000

// when using middleware `hostname` and `port` must be provided below
const app = next({ dev, hostname, port })
const handle = app.getRequestHandler()

app.prepare().then(() => {
  createServer(async (req, res) => {
    try {
      // Be sure to pass `true` as the second argument to `url.parse`.
      // This tells it to parse the query portion of the URL.
      const parsedUrl = parse(req.url, true)
      const { pathname, query } = parsedUrl

      if (pathname === '/sub/hello') {
        await app.render(req, res, '/sub/[id]', query)
      } else {
        await handle(req, res, parsedUrl)
      }
    } catch (err) {
      console.error('Error occurred handling', req.url, err)
      res.statusCode = 500
      res.end('internal server error')
    }
  }).listen(port, (err) => {
    if (err) throw err
    console.log(`> Ready on http://${hostname}:${port}`)
  })
})

pages/sub/[id].js

export default function Page() {
  return <span>Welcome to this dynamic page</span>
}

[scripter-co]

spent quite a bit of time investigating and coming to the same conclusion as the above. created another reproducible repo here: https://github.com/scripter-co/express-nextjs-dynamic-routes

[rtrys]

maintainers, is there any update?