Disabling file-system routing affects serving files from the public directory

[ussuritiger]

Bug report

Describe the bug

According to the documentation setting the useFileSystemPublicRoutes configuration option to false prevents routing based on files in /pages directory. If this option is set to false in combination with using a custom server, images (and most likely other file types) are not served from the /public directory. The 404 page is served instead.

To Reproduce

1. Use an example with custom server (tested with Fastify)
2. Create /public directory with an image inside
3. Add HTML image tag with the /image-name as src attribute to any page
4. Add next.config.js file to the root with the following content:

module.exports = {
  useFileSystemPublicRoutes: false
}

5. Open modified page in the browser

Expected behavior

Image is shown regardless of useFileSystemPublicRoutes configuration option's value.

[AaronDDM]

I am able to replicate this - it's because of:
https://github.com/zeit/next.js/blob/canary/packages/next/next-server/server/next-server.ts#L560

Essentially the "catch all" is only included if useFileSystemPublicRoutes is set to true - however DevServer relies on "catch all" to serve files from the public folder.

Because we do not rely on the catch all method for production - this issue doesn't occur in production for serving files from the public folder.

Q: Anyone see any issue with moving routes.push(catchAllRoute); outside of the useFileSystemPublicRoutes check?

[balazsorban44]

This issue has been automatically locked due to no recent activity. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.