From 244e8b7b5aa10b049246ca51daed5d3eba02001d Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Mon, 2 Nov 2026 20:15:34 +0100
Subject: [PATCH] fix: keep the login and mailbox owner in notification links
 on safari 16 #1499

---
 lib/__tests__/helpers/push-click.ts | 8 ++++++--
 lib/__tests__/sw-push-owner.test.ts | 5 +++++
 public/sw.js                        | 4 +++-
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/__tests__/helpers/push-click.ts b/lib/__tests__/helpers/push-click.ts
index 7509a9c73..369efd6a2 100644
--- a/lib/__tests__/helpers/push-click.ts
+++ b/lib/__tests__/helpers/push-click.ts
@@ -5,7 +5,7 @@ import vm from 'node:vm';
 export async function pushClick(
   accountId: string,
   preview: (url: string) => Promise<unknown>,
-  options: { warm?: boolean; basePath?: string; legacy?: boolean; emailId?: string } = {},
+  options: { warm?: boolean; basePath?: string; legacy?: boolean; emailId?: string; noParamsSize?: boolean } = {},
 ): Promise<string> {
   const source = readFileSync(resolve('public/sw.js'), 'utf8');
   let notification: { data: unknown } | undefined;
@@ -18,8 +18,12 @@ export async function pushClick(
     async focus() { return this; },
     async navigate(url: string) { target = url; return this; },
   };
+  // Safari before 17 has no URLSearchParams.size.
+  const SearchParams = options.noParamsSize
+    ? class extends URLSearchParams { get size(): number { return undefined as unknown as number; } }
+    : URLSearchParams;
   const context = vm.createContext({
-    URL, URLSearchParams, Response, AbortController, setTimeout, clearTimeout, console,
+    URL, URLSearchParams: SearchParams, Response, AbortController, setTimeout, clearTimeout, console,
     self: {
       location: { href: `https://mail.example.test${options.basePath ?? ''}/sw.js`, origin: 'https://mail.example.test' },
       addEventListener: (type: string, fn: (event: unknown) => void) => listeners.set(type, fn),
diff --git a/lib/__tests__/sw-push-owner.test.ts b/lib/__tests__/sw-push-owner.test.ts
index ace7cf58d..ade1e246a 100644
--- a/lib/__tests__/sw-push-owner.test.ts
+++ b/lib/__tests__/sw-push-owner.test.ts
@@ -47,6 +47,11 @@ describe('push click keeps the owning mailbox (#1491)', () => {
     expect(parseTarget(target)).toMatchObject({ kind: 'folder', ownerAccountId: 'team', slot: 2 });
   });
 
+  it('keeps the slot and owner where URLSearchParams has no size', async () => {
+    const target = await pushClick('team', async () => ({ slot: 1, unreadTotal: 1, email: { id: 'same-id' } }), { noParamsSize: true });
+    expect(parseTarget(target)).toMatchObject({ kind: 'message', ownerAccountId: 'team', slot: 1 });
+  });
+
   it('does not fall back to a personal folder for an unavailable owner', () => {
     expect(resolveFolderRef('inbox', folders, 'unavailable')).toBeNull();
   });
diff --git a/public/sw.js b/public/sw.js
index 975db0c27..3dc7ff7b8 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -925,7 +925,9 @@ function buildClickUrl(data) {
   const params = new URLSearchParams();
   if (Number.isInteger(data.slot)) params.set("slot", String(data.slot));
   if (typeof data.accountId === "string" && data.accountId) params.set("owner", data.accountId);
-  const targetQuery = params.size ? `?${params}` : "";
+  // Not params.size: Safari before 17 (iOS 16.4+ web push) lacks it.
+  const qs = params.toString();
+  const targetQuery = qs ? `?${qs}` : "";
   if (data.kind === "email" && data.emailId) {
     // Permalink (#733). Under NEXT_PUBLIC_LOCALE_PREFIX=always the proxy
     // redirects this to the localised path; the worker has no locale to add.