Error Invalid character in header content ["Location"] with trailingSlash enabled

What version of Next.js are you using?

11.1.2

What version of Node.js are you using?

12.18.1

What browser are you using?

Brave

What operating system are you using?

macOS

How are you deploying your application?

next start

Describe the Bug

When the trailingSlash is enabled, the redirection doesn’t work properly in some of the cases.

Example URL:

http://localhost:3000/some-url/%E2%80%9Chttps://domain.com/analytics?pxid=111&%E2%80%9D

Returned error:

error - TypeError [ERR_INVALID_CHAR]: Invalid character in header content ["Location"]
    at ServerResponse.setHeader (_http_outgoing.js:521:3)
    at Object.fn (/Library/WebServer/Documents/nextjs/node_modules/next/dist/server/next-server.js:554:25)
    at Router.execute (/Library/WebServer/Documents/nextjs/node_modules/next/dist/server/router.js:205:48)
    at DevServer.run (/Library/WebServer/Documents/nextjs/node_modules/next/dist/server/next-server.js:841:47)
    at DevServer.run (/Library/WebServer/Documents/nextjs/node_modules/next/dist/server/dev/next-dev-server.js:355:32)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async DevServer.handleRequest (/Library/WebServer/Documents/nextjs/node_modules/next/dist/server/next-server.js:292:20) {
  code: 'ERR_INVALID_CHAR'
}

Expected Behavior

All of the URLS tried to be accessed are properly redirected without any errors thrown.

To Reproduce

1. npm install next@11.1.2 react react-dom
2. create a sample index page
3. create a next.config.js file:

module.exports = {
  trailingSlash: true,
};

1. npm run dev
2. Visit the below URL in the browser:

http://localhost:3000/some-url/%E2%80%9Chttps://domain.com/analytics?pxid=111&%E2%80%9D

1. See the error

[tills13]

Is it invalid?

The query is ?pxid=111&%E2%80%9D' which is parsed into { 'pxid' => '111', '”' => '' }

Per https://url.spec.whatwg.org/#concept-urlencoded-parser (and is the behaviour of URL)

> const u = new URL('http://localhost:3000/some-url/%E2%80%9Chttps://domain.com/analytics?pxid=111&%E2%80%9D')
> u.search
'?pxid=111&%E2%80%9D'
> u.searchParams
URLSearchParams { 'pxid' => '111', '”' => '' }

At the very least, NextJS shouldn’t encounter an error in this situation.

[github-actions[bot]]

Please verify that your issue can be recreated with next@canary.

Why was this issue marked with the please verify canary label?

We noticed the provided reproduction was using an older version of Next.js, instead of canary.

The canary version of Next.js ships daily and includes all features and fixes that have not been released to the stable version yet. You can think of canary as a public beta. Some issues may already be fixed in the canary version, so please verify that your issue reproduces by running npm install next@canary and test it in your project, using your reproduction steps.

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• How to Contribute to Open Source (Next.js)
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• Reporting a Next.js bug
• Next.js Triaging issues