Fix Link generation for SSG pages if locale domains are used

packages/next/export/worker.ts

@@ -2,7 +2,7 @@ import type { ComponentType } from 'react'
 import type { FontManifest } from '../server/font-utils'
 import type { GetStaticProps } from '../types'
 import type { IncomingMessage, ServerResponse } from 'http'
-import type { NextConfigComplete } from '../server/config-shared'
+import type { DomainLocale, NextConfigComplete } from '../server/config-shared'
 import type { NextParsedUrlQuery } from '../server/request-meta'
 import url from 'url'
 import { extname, join, dirname, sep } from 'path'
@@ -23,6 +23,7 @@ import { isInAmpMode } from '../shared/lib/amp-mode'
 import { setHttpAgentOptions } from '../server/config'
 import RenderResult from '../server/render-result'
 import isError from '../lib/is-error'
+import { addRequestMeta } from '../server/request-meta'
 
 const envConfig = require('../shared/lib/runtime-config')
 
@@ -84,6 +85,7 @@ interface RenderOpts {
   locales?: string[]
   locale?: string
   defaultLocale?: string
+  domainLocales?: DomainLocale[]
   trailingSlash?: boolean
   appDir?: boolean
 }
@@ -208,6 +210,18 @@ export default async function exportPage({
         req.url += '/'
       }
 
+      if (
+        locale &&
+        buildExport &&
+        renderOpts.domainLocales &&
+        renderOpts.domainLocales.some(
+          (dl) =>
+            dl.defaultLocale === locale || dl.locales?.includes(locale || '')
+        )
+      ) {
+        addRequestMeta(req, '__nextIsLocaleDomain', true)
+      }
+
       envConfig.setConfig({
         serverRuntimeConfig,
         publicRuntimeConfig: renderOpts.runtimeConfig,

test/integration/i18n-support/test/shared.js

@@ -407,6 +407,49 @@ export function runTests(ctx) {
     }
   })
 
+  // The page is accessible on subpath as well as on the domain url without subpath.
+  // Once this is not the case the test will need to be changed to access it via domain.
+  // Beware of the different expectations on dev and prod version since the pre-rendering on dev does not work with domain locales
+  it('should prerender with the correct href for locale domain', async () => {
+    let browser = await webdriver(ctx.appPort, `${ctx.basePath || ''}/go`)
+
+    for (const [element, pathname] of [
+      ['#to-another', '/another'],
+      ['#to-gsp', '/gsp'],
+      ['#to-fallback-first', '/gsp/fallback/first'],
+      ['#to-fallback-hello', '/gsp/fallback/hello'],
+      ['#to-gssp', '/gssp'],
+      ['#to-gssp-slug', '/gssp/first'],
+    ]) {
+      const href = await browser.elementByCss(element).getAttribute('href')
+      if (ctx.isDev) {
+        expect(href).toBe(`${ctx.basePath || ''}/go${pathname}`)
+      } else {
+        expect(href).toBe(`https://example.com${ctx.basePath || ''}${pathname}`)
+      }
+    }
+
+    browser = await webdriver(ctx.appPort, `${ctx.basePath || ''}/go-BE`)
+
+    for (const [element, pathname] of [
+      ['#to-another', '/another'],
+      ['#to-gsp', '/gsp'],
+      ['#to-fallback-first', '/gsp/fallback/first'],
+      ['#to-fallback-hello', '/gsp/fallback/hello'],
+      ['#to-gssp', '/gssp'],
+      ['#to-gssp-slug', '/gssp/first'],
+    ]) {
+      const href = await browser.elementByCss(element).getAttribute('href')
+      if (ctx.isDev) {
+        expect(href).toBe(`${ctx.basePath || ''}/go-BE${pathname}`)
+      } else {
+        expect(href).toBe(
+          `https://example.com${ctx.basePath || ''}/go-BE${pathname}`
+        )
+      }
+    }
+  })
+
   it('should render the correct href with locale domains but not on a locale domain', async () => {
     let browser = await webdriver(
       ctx.appPort,