From 1167523f01ed6363c3fe3bbb7aa925744eedd055 Mon Sep 17 00:00:00 2001
From: Jan Amann <jan@amann.work>
Date: Thu, 1 Feb 2024 09:30:09 +0100
Subject: [PATCH] fix: Keep cookie value in sync when navigating within a
 locale (#828)

Fixes #826
---
 packages/next-intl/package.json                               | 4 ++--
 packages/next-intl/src/navigation/shared/syncLocaleCookie.tsx | 2 +-
 .../test/navigation/react-client/useBaseRouter.test.tsx       | 3 +++
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/next-intl/package.json b/packages/next-intl/package.json
index dbfb060da..9063a38b4 100644
--- a/packages/next-intl/package.json
+++ b/packages/next-intl/package.json
@@ -122,11 +122,11 @@
     },
     {
       "path": "dist/production/navigation.react-client.js",
-      "limit": "2.83 KB"
+      "limit": "2.84 KB"
     },
     {
       "path": "dist/production/navigation.react-server.js",
-      "limit": "2.94 KB"
+      "limit": "2.95 KB"
     },
     {
       "path": "dist/production/server.react-client.js",
diff --git a/packages/next-intl/src/navigation/shared/syncLocaleCookie.tsx b/packages/next-intl/src/navigation/shared/syncLocaleCookie.tsx
index 8cebf57c2..9ca242d8a 100644
--- a/packages/next-intl/src/navigation/shared/syncLocaleCookie.tsx
+++ b/packages/next-intl/src/navigation/shared/syncLocaleCookie.tsx
@@ -14,7 +14,7 @@ export default function syncLocaleCookie(
   locale: string,
   nextLocale?: string
 ) {
-  const isSwitchingLocale = nextLocale !== locale;
+  const isSwitchingLocale = nextLocale !== locale && nextLocale != null;
 
   if (
     !isSwitchingLocale ||
diff --git a/packages/next-intl/test/navigation/react-client/useBaseRouter.test.tsx b/packages/next-intl/test/navigation/react-client/useBaseRouter.test.tsx
index 581f23cab..adae5051f 100644
--- a/packages/next-intl/test/navigation/react-client/useBaseRouter.test.tsx
+++ b/packages/next-intl/test/navigation/react-client/useBaseRouter.test.tsx
@@ -95,6 +95,9 @@ describe('unprefixed routing', () => {
     callRouter((router) => router.push('/about', {locale: 'de'}));
     expect(document.cookie).toContain('NEXT_LOCALE=de');
 
+    callRouter((router) => router.push('/test'));
+    expect(document.cookie).toContain('NEXT_LOCALE=de');
+
     callRouter((router) => router.replace('/about', {locale: 'es'}));
     expect(document.cookie).toContain('NEXT_LOCALE=es');