From bcb20100dbb6c6b43ecbc46e8ee8d236ad724f15 Mon Sep 17 00:00:00 2001
From: Shu Ding <g@shud.in>
Date: Thu, 23 Feb 2023 16:55:58 +0100
Subject: [PATCH] Fix error on 404 page when middleware exists (#46303)

Closes #44293.

## Bug

- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] [e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs) tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm build && pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)
---
 packages/next/src/shared/lib/router/router.ts |  8 ++++----
 test/e2e/404-page-router/index.test.ts        | 11 +++++++++++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/packages/next/src/shared/lib/router/router.ts b/packages/next/src/shared/lib/router/router.ts
index 4a31ac69c10b..857288a96e20 100644
--- a/packages/next/src/shared/lib/router/router.ts
+++ b/packages/next/src/shared/lib/router/router.ts
@@ -1456,6 +1456,8 @@ export default class Router implements BaseRouter {
       Router.events.emit('routeChangeStart', as, routeProps)
     }
 
+    const isErrorRoute = this.pathname === '/404' || this.pathname === '/_error'
+
     try {
       let routeInfo = await this.getRouteInfo({
         route,
@@ -1645,10 +1647,7 @@ export default class Router implements BaseRouter {
       // wasn't originally present. This is also why this block is before the
       // below `changeState` call which updates the browser's history (changing
       // the URL).
-      if (
-        isQueryUpdating &&
-        (this.pathname === '/404' || this.pathname === '/_error')
-      ) {
+      if (isQueryUpdating && isErrorRoute) {
         routeInfo = await this.getRouteInfo({
           route: this.pathname,
           pathname: this.pathname,
@@ -1658,6 +1657,7 @@ export default class Router implements BaseRouter {
           routeProps: { shallow: false },
           locale: nextState.locale,
           isPreview: nextState.isPreview,
+          isQueryUpdating: isQueryUpdating && !this.isFallback,
         })
 
         if ('type' in routeInfo) {
diff --git a/test/e2e/404-page-router/index.test.ts b/test/e2e/404-page-router/index.test.ts
index 6cde04efcf40..5c69e310cd77 100644
--- a/test/e2e/404-page-router/index.test.ts
+++ b/test/e2e/404-page-router/index.test.ts
@@ -118,5 +118,16 @@ describe.each(table)(
         }
       })
     })
+
+    // It should not throw any errors when re-fetching the route info:
+    // https://github.com/vercel/next.js/issues/44293
+    it('should not throw any errors when re-fetching the route info', async () => {
+      const browser = await webdriver(next.url, '/?test=1')
+      await check(
+        () => browser.eval('next.router.isReady ? "yes" : "no"'),
+        'yes'
+      )
+      expect(await browser.elementById('query').text()).toEqual('test=1')
+    })
   }
 )