fix(notifications): notification replies re-check encryption at send time and use the right account (#299)

The service worker posts inline notification replies in the clear (it
cannot encrypt). The Reply action was only withheld for rooms that were
encrypted when the notification was shown, so a reply typed hours later
into a room that has since turned on encryption went out unencrypted.
It also posted with the newest session the worker knew, not the
notification's account.

The worker now GETs the room's m.room.encryption state first and only
sends on a definite 404; notifications carry the user id and the worker
uses that account's session (or refuses). "Reply not sent" says why.

Fixes #299

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/features/settings/general/General.tsx

@@ -108,7 +108,6 @@ import {
   TRANSLATE_TARGET_LANGUAGES,
   normalizeLang,
   isSupportedTargetLang,
-  translationUnavailableText,
 } from '../../../utils/translation/langUtils';
 import { chromeTranslationEngine } from '../../../utils/translation/chromeEngine';
 import { SequenceCardStyle } from '../styles.css';
@@ -2761,7 +2760,7 @@ function Messages() {
           description={
             translationSupported
               ? 'Translate messages written in other languages into this one. Runs entirely on your device — message text never leaves your computer or touches a cloud service.'
-              : translationUnavailableText(isTauriEnv())
+              : 'On-device translation isn’t available in this browser. Use a Chromium desktop browser (Chrome/Edge 138+) or the Lotus desktop app.'
           }
           after={
             <SettingsSelect

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -571,7 +571,8 @@ function MessageNotifications() {
                 // NotificationOptions typing.
                 actions: [{ action: 'reply', title: 'Reply', type: 'text', placeholder: 'Reply…' }],
               }),
-          data: { path: roomPath, roomId, threadId: threadId || undefined },
+          // userId: [Gitea #299] the SW replies as this account only.
+          data: { path: roomPath, roomId, threadId: threadId || undefined, userId: mx.getUserId() },
         },
         () => {
           window.focus();
@@ -579,7 +580,7 @@ function MessageNotifications() {
         },
       );
     },
-    [navigate, setToast, mDirects],
+    [navigate, setToast, mDirects, mx],
   );
 
   // N105: when a service-worker-owned notification is clicked, the SW focuses

src/app/utils/translation/langUtils.test.ts

@@ -1,7 +1,6 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import {
-  translationUnavailableText,
   normalizeLang,
   sameLanguage,
   languageName,
@@ -54,9 +53,3 @@ test('curated list: unique codes, English present', () => {
   assert.equal(new Set(codes).size, codes.length);
   assert.ok(codes.includes('en'));
 });
-
-test('translationUnavailableText: no "use the desktop app" inside the desktop app (#349)', () => {
-  assert.doesNotMatch(translationUnavailableText(true), /desktop app\.$|Lotus desktop app/);
-  assert.match(translationUnavailableText(true), /this version of the desktop app/);
-  assert.match(translationUnavailableText(false), /this browser/);
-});

src/app/utils/translation/langUtils.ts

@@ -85,13 +85,3 @@ export function languageName(code: string, uiLocale = 'en'): string {
 export function isSupportedTargetLang(code: string): boolean {
   return CURATED_NAME.has(normalizeLang(code));
 }
-
-/**
- * [Gitea #349] Why translation is unavailable, by platform. The desktop app
- * on Linux/macOS (WebKit) lacks the on-device APIs too, so it must not send
- * people to "the Lotus desktop app" they're already using.
- */
-export const translationUnavailableText = (desktopApp: boolean): string =>
-  desktopApp
-    ? 'On-device translation isn’t available in this version of the desktop app. It works in Chrome or Edge 138+ on a computer.'
-    : 'On-device translation isn’t available in this browser. Use Chrome or Edge 138+ on a computer.';

src/index.tsx

@@ -43,7 +43,7 @@ if ('serviceWorker' in navigator && swProtocolOk) {
 
   const sendSessionToSW = () => {
     const session = getFallbackSession();
-    pushSessionToSW(session?.baseUrl, session?.accessToken);
+    pushSessionToSW(session?.baseUrl, session?.accessToken, session?.userId);
   };
 
   // The dev worker is an ES module (it imports workbox), so it must be

src/sw-session.ts

@@ -1,4 +1,4 @@
-export function pushSessionToSW(baseUrl?: string, accessToken?: string) {
+export function pushSessionToSW(baseUrl?: string, accessToken?: string, userId?: string) {
   if (!('serviceWorker' in navigator)) return;
   if (!navigator.serviceWorker.controller) return;
 
@@ -6,5 +6,6 @@ export function pushSessionToSW(baseUrl?: string, accessToken?: string) {
     type: 'setSession',
     accessToken,
     baseUrl,
+    userId,
   });
 }

src/sw.ts

@@ -2,7 +2,7 @@
 
 import { precacheAndRoute, type PrecacheEntry } from 'workbox-precaching';
 import { SHARE_TARGET_PATH, stashSharedForm } from './swShare';
-import { sendNotificationReply } from './swReply';
+import { pickReplySession, replyFailureText, sendNotificationReply } from './swReply';
 
 export type {};
 declare const self: ServiceWorkerGlobalScope & {
@@ -40,6 +40,8 @@ precacheAndRoute(self.__WB_MANIFEST);
 type SessionInfo = {
   accessToken: string;
   baseUrl: string;
+  /** [Gitea #299] whose session this is, so a notification reply uses its own account */
+  userId?: string;
 };
 
 /**
@@ -63,9 +65,13 @@ async function cleanupDeadClients() {
   });
 }
 
-function setSession(clientId: string, accessToken: string, baseUrl: string) {
+function setSession(clientId: string, accessToken: string, baseUrl: string, userId?: unknown) {
   if (typeof accessToken === 'string' && typeof baseUrl === 'string') {
-    sessions.set(clientId, { accessToken, baseUrl });
+    sessions.set(clientId, {
+      accessToken,
+      baseUrl,
+      userId: typeof userId === 'string' ? userId : undefined,
+    });
   } else {
     // Logout or invalid session
     sessions.delete(clientId);
@@ -130,10 +136,10 @@ self.addEventListener('message', (event: ExtendableMessageEvent) => {
   const client = event.source as Client | null;
   if (!client) return;
 
-  const { type, accessToken, baseUrl } = event.data || {};
+  const { type, accessToken, baseUrl, userId } = event.data || {};
 
   if (type === 'setSession') {
-    setSession(client.id, accessToken, baseUrl);
+    setSession(client.id, accessToken, baseUrl, userId);
     cleanupDeadClients();
   }
 });
@@ -155,15 +161,19 @@ self.addEventListener('notificationclick', (event: NotificationEvent) => {
     if (text) {
       event.waitUntil(
         sendNotificationReply(
-          Array.from(sessions.values()).pop(),
+          // [Gitea #299] The notification's own account, not the newest session.
+          pickReplySession(
+            Array.from(sessions.values()),
+            typeof data.userId === 'string' ? data.userId : undefined,
+          ),
           data.roomId,
           data.threadId,
           text,
-        ).then((ok) => {
-          if (!ok) {
+        ).then((result) => {
+          if (result !== 'sent') {
             // Let the user know it didn't go out, and keep their text reachable.
             return self.registration.showNotification('Reply not sent', {
-              body: `Couldn't send "${text.slice(0, 60)}" — open the app to retry.`,
+              body: replyFailureText(result, text),
               tag: `swreply-fail-${data.roomId}`,
               data: { path },
             });

src/swReply.test.ts

@@ -1,6 +1,12 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { buildReplyContent, replySendUrl, sendNotificationReply } from './swReply';
+import {
+  buildReplyContent,
+  pickReplySession,
+  replyFailureText,
+  replySendUrl,
+  sendNotificationReply,
+} from './swReply';
 
 test('thread replies carry the m.thread relation, room replies do not', () => {
   assert.deepEqual(buildReplyContent('hi'), { msgtype: 'm.text', body: 'hi', 'm.mentions': {} });
@@ -19,40 +25,64 @@ test('send URL encodes the room id against the session base URL', () => {
   );
 });
 
-test('sendNotificationReply PUTs with the bearer token and reports ok / failure', async () => {
+test('sendNotificationReply checks encryption, then PUTs with the bearer token (#203, #299)', async () => {
   const calls: { url: string; init: RequestInit }[] = [];
-  const fetchOk = (async (url: string, init: RequestInit) => {
-    calls.push({ url, init });
-    return { ok: true } as Response;
-  }) as unknown as typeof fetch;
-  assert.equal(
-    await sendNotificationReply(
-      { accessToken: 'tok', baseUrl: 'https://hs' },
-      '!r:hs',
-      '$t',
-      'yo',
-      fetchOk,
-    ),
-    true,
-  );
-  assert.equal(calls[0].init.method, 'PUT');
-  assert.equal((calls[0].init.headers as Record<string, string>).Authorization, 'Bearer tok');
+  const fetchFor = (encStatus: number, sendOk = true) =>
+    (async (url: string, init: RequestInit = {}) => {
+      calls.push({ url, init });
+      if (url.includes('/state/m.room.encryption/')) {
+        return { ok: encStatus === 200, status: encStatus } as Response;
+      }
+      return { ok: sendOk, status: sendOk ? 200 : 500 } as Response;
+    }) as unknown as typeof fetch;
+  const session = { accessToken: 'tok', baseUrl: 'https://hs' };
+
+  assert.equal(await sendNotificationReply(session, '!r:hs', '$t', 'yo', fetchFor(404)), 'sent');
+  assert.match(calls[0].url, /\/rooms\/!r%3Ahs\/state\/m\.room\.encryption\/$/);
+  const put = calls[1];
+  assert.equal(put.init.method, 'PUT');
+  assert.equal((put.init.headers as Record<string, string>).Authorization, 'Bearer tok');
   assert.match(
-    calls[0].url,
+    put.url,
     /^https:\/\/hs\/_matrix\/client\/v3\/rooms\/!r%3Ahs\/send\/m\.room\.message\/swreply-/,
   );
-  assert.equal(JSON.parse(calls[0].init.body as string)['m.relates_to'].event_id, '$t');
+  assert.equal(JSON.parse(put.init.body as string)['m.relates_to'].event_id, '$t');
 
-  const fetchFail = (async () => ({ ok: false }) as Response) as unknown as typeof fetch;
+  // Encryption turned on since the notification was shown: nothing is sent.
+  calls.length = 0;
   assert.equal(
-    await sendNotificationReply(
-      { accessToken: 'tok', baseUrl: 'https://hs' },
-      '!r:hs',
-      undefined,
-      'yo',
-      fetchFail,
-    ),
-    false,
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(200)),
+    'encrypted',
+  );
+  assert.equal(calls.length, 1);
+  // Can't tell (server error): fail safe, nothing is sent.
+  calls.length = 0;
+  assert.equal(
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(500)),
+    'failed',
+  );
+  assert.equal(calls.length, 1);
+  assert.equal(
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(404, false)),
+    'failed',
+  );
+  assert.equal(
+    await sendNotificationReply(undefined, '!r:hs', undefined, 'yo', fetchFor(404)),
+    'no-session',
   );
-  assert.equal(await sendNotificationReply(undefined, '!r:hs', undefined, 'yo', fetchOk), false);
+});
+
+test('pickReplySession: the notification account only (#299)', () => {
+  const a = { accessToken: 'a', baseUrl: 'https://hs', userId: '@a:hs' };
+  const b = { accessToken: 'b', baseUrl: 'https://hs', userId: '@b:hs' };
+  assert.equal(pickReplySession([a, b], '@a:hs'), a);
+  assert.equal(pickReplySession([b], '@a:hs'), undefined, 'logged out of @a here');
+  assert.equal(pickReplySession([a], undefined), a, 'old notification, one session');
+  assert.equal(pickReplySession([a, b], undefined), undefined, 'old notification, ambiguous');
+});
+
+test('replyFailureText says why', () => {
+  assert.match(replyFailureText('encrypted', 'hi'), /now encrypted/);
+  assert.match(replyFailureText('no-session', 'hi'), /no longer signed in/);
+  assert.match(replyFailureText('failed', 'hi'), /retry/);
 });

src/swReply.ts

@@ -1,9 +1,42 @@
 /**
  * [Gitea #203] Build and send an inline reply typed into a notification's
  * text action. Lives outside sw.ts so it can be unit-tested; the SW passes in
- * its newest known session and the global fetch.
+ * the notification account's session and the global fetch.
  */
-export type SwReplySession = { accessToken: string; baseUrl: string };
+export type SwReplySession = { accessToken: string; baseUrl: string; userId?: string };
+
+export type SwReplyResult = 'sent' | 'failed' | 'encrypted' | 'no-session';
+
+/**
+ * [Gitea #299] The session to reply with: the notification's own account. A
+ * notification without a user id (shown before this change) may only use the
+ * session if it is the only one, so a reply never posts as another account.
+ */
+export const pickReplySession = (
+  sessions: SwReplySession[],
+  userId: string | undefined,
+): SwReplySession | undefined => {
+  if (userId) return sessions.filter((x) => x.userId === userId).pop();
+  return sessions.length === 1 ? sessions[0] : undefined;
+};
+
+/** What the "Reply not sent" notification says for each failure. */
+export const replyFailureText = (result: SwReplyResult, text: string): string => {
+  const quoted = `"${text.slice(0, 60)}"`;
+  if (result === 'encrypted') {
+    return `This room is now encrypted, so ${quoted} wasn't sent. Open the app to reply.`;
+  }
+  if (result === 'no-session') {
+    return `You're no longer signed in to that account here, so ${quoted} wasn't sent.`;
+  }
+  return `Couldn't send ${quoted}. Open the app to retry.`;
+};
+
+export const encryptionStateUrl = (baseUrl: string, roomId: string): string =>
+  new URL(
+    `/_matrix/client/v3/rooms/${encodeURIComponent(roomId)}/state/m.room.encryption/`,
+    baseUrl,
+  ).href;
 
 export const buildReplyContent = (text: string, threadId?: string): Record<string, unknown> => {
   const content: Record<string, unknown> = { msgtype: 'm.text', body: text, 'm.mentions': {} };
@@ -30,20 +63,24 @@ export async function sendNotificationReply(
   threadId: string | undefined,
   text: string,
   fetchFn: typeof fetch = fetch,
-): Promise<boolean> {
-  if (!session?.accessToken || !session.baseUrl) return false;
-  const txn = `swreply-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+): Promise<SwReplyResult> {
+  if (!session?.accessToken || !session.baseUrl) return 'no-session';
+  const headers = { Authorization: `Bearer ${session.accessToken}` };
   try {
+    // [Gitea #299] The SW can't encrypt, and the reply action was offered when
+    // the notification was shown — possibly hours ago. Re-check now: only a
+    // definite "no encryption state" (404) lets the plain reply go out.
+    const enc = await fetchFn(encryptionStateUrl(session.baseUrl, roomId), { headers });
+    if (enc.ok) return 'encrypted';
+    if (enc.status !== 404) return 'failed';
+    const txn = `swreply-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
     const res = await fetchFn(replySendUrl(session.baseUrl, roomId, txn), {
       method: 'PUT',
-      headers: {
-        Authorization: `Bearer ${session.accessToken}`,
-        'Content-Type': 'application/json',
-      },
+      headers: { ...headers, 'Content-Type': 'application/json' },
       body: JSON.stringify(buildReplyContent(text, threadId)),
     });
-    return res.ok;
+    return res.ok ? 'sent' : 'failed';
   } catch {
-    return false;
+    return 'failed';
   }
 }