bug (#21943): remove incorrect rewrite of parsedUrl.pathname in serve…

…rless handler (#22445)

Fixes #21943

i confirmed in a personal test repo that this solves the issue of infinite 307s on root level non-default locales :)  let me know what else this needs if anything! thanks for the time/help @ijjk ❤️

packages/next/build/webpack/loaders/next-serverless-loader/utils.ts

@@ -333,6 +333,7 @@ export function getUtils({
     shouldNotRedirect: boolean
   ) {
     if (!i18n) return
+    const pathname = parsedUrl.pathname || '/'
 
     let defaultLocale = i18n.defaultLocale
     let detectedLocale = detectLocaleCookie(req, i18n.locales)
@@ -356,10 +357,7 @@ export function getUtils({
     detectedLocale = detectedLocale || acceptPreferredLocale
 
     let localeDomainRedirect
-    const localePathResult = normalizeLocalePath(
-      parsedUrl.pathname!,
-      i18n.locales
-    )
+    const localePathResult = normalizeLocalePath(pathname, i18n.locales)
 
     routeNoAssetPath = normalizeLocalePath(routeNoAssetPath, i18n.locales)
       .pathname
@@ -395,7 +393,7 @@ export function getUtils({
       }
     }
 
-    const denormalizedPagePath = denormalizePagePath(parsedUrl.pathname || '/')
+    const denormalizedPagePath = denormalizePagePath(pathname)
     const detectedDefaultLocale =
       !detectedLocale ||
       detectedLocale.toLowerCase() === defaultLocale.toLowerCase()

test/integration/i18n-support-catchall/test/index.test.js

@@ -315,11 +315,16 @@ describe('i18n Support Root Catch-all', () => {
         redirect: 'manual',
       })
 
+      const res4 = await fetchViaHTTP(port, '/fr', undefined, {
+        redirect: 'manual',
+      })
+
       server.close()
 
       expect(res.status).toBe(200)
       expect(res2.status).toBe(200)
       expect(res3.status).toBe(200)
+      expect(res4.status).toBe(200)
 
       const $ = cheerio.load(await res.text())
       const $2 = cheerio.load(await res2.text())