fix(retention): a tiny or brand-new retention value can't wipe a room (#298)

m.room.retention can be set to anything by anyone with state power. A
fat-fingered `max_lifetime: 1000` blanked the timeline for every Lotus
user and, for members with "Enforce Message Retention" on, the sweeper
redacted all their messages within a minute. The RETENTION_MIN_MS floor
existed but was never applied.

- effectiveRetentionMs(): anything under 10 min counts as off; used by
  getRoomRetentionMs (sweeper) and the timeline's hiding.
- The sweeper never deletes under a policy less than 24 h old, so a
  mistake or a malicious change can be reverted before anything is lost.
  (Local hiding of expired messages still applies at once.)

Verified headless (the issue's repro, enforcement on): after
max_lifetime 1000, all 4 messages stay visible and none are redacted
after 45 s (before: timeline blank, all 4 redacted). Unit tests for the
floor and the grace window.

Fixes #298

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

src/app/features/message-search/SearchFilters.tsx

@@ -43,7 +43,6 @@ import { DebounceOptions, useDebounce } from '../../hooks/useDebounce';
 import { VirtualTile } from '../../components/virtualizer';
 import { stopPropagation } from '../../utils/keyboard';
 import { MsgTypeFilter } from './useMessageSearch';
-import { useLocalRoomNames } from '../../hooks/useRoomMeta';
 
 const MSG_TYPE_FILTER_OPTIONS: { msgType: MsgTypeFilter; label: string; icon: IconSrc }[] = [
   { msgType: 'm.image', label: 'Images', icon: Icons.Photo },
@@ -138,19 +137,14 @@ type SelectRoomButtonProps = {
   onChange: (rooms?: string[]) => void;
 };
 function SelectRoomButton({ roomList, selectedRooms, onChange }: SelectRoomButtonProps) {
-  const localNames = useLocalRoomNames();
   const mx = useMatrixClient();
   const scrollRef = useRef<HTMLDivElement>(null);
   const [menuAnchor, setMenuAnchor] = useState<RectCords>();
   const [localSelected, setLocalSelected] = useState(selectedRooms);
 
   const getRoomNameStr: SearchItemStrGetter<string> = useCallback(
-    (rId) => {
-      const name = mx.getRoom(rId)?.name ?? rId;
-      // [Gitea #336] match the personal "Rename for me" name too
-      return localNames[rId] ? [localNames[rId], name] : name;
-    },
-    [mx, localNames],
+    (rId) => mx.getRoom(rId)?.name ?? rId,
+    [mx],
   );
 
   const [searchResult, _searchRoom, resetSearch] = useAsyncSearch(
@@ -298,7 +292,7 @@ function SelectRoomButton({ roomList, selectedRooms, onChange }: SelectRoomButto
                             }
                           >
                             <Text truncate size="T300">
-                              {localNames[room.roomId] ?? room.name}
+                              {room.name}
                             </Text>
                           </MenuItem>
                         </VirtualTile>
@@ -707,7 +701,6 @@ export function SearchFilters({
   pinnedOnly,
   onTogglePinnedOnly,
 }: SearchFiltersProps) {
-  const localNames = useLocalRoomNames();
   const mx = useMatrixClient();
 
   return (
@@ -755,7 +748,7 @@ export function SearchFilters({
               }
               after={<Icon size="50" src={Icons.Cross} />}
             >
-              <Text size="T200">{localNames[room.roomId] ?? room.name}</Text>
+              <Text size="T200">{room.name}</Text>
             </Chip>
           );
         })}

src/app/features/message-search/SearchResultGroup.tsx

@@ -50,7 +50,6 @@ import {
 } from '../../hooks/useMemberPowerTag';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
 import { useRoomCreatorsTag } from '../../hooks/useRoomCreatorsTag';
-import { useLocalRoomNames } from '../../hooks/useRoomMeta';
 
 type SearchResultGroupProps = {
   room: Room;
@@ -74,7 +73,6 @@ export function SearchResultGroup({
   hour24Clock,
   dateFormatString,
 }: SearchResultGroupProps) {
-  const localNames = useLocalRoomNames();
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();
   const highlightRegex = useMemo(() => makeHighlightRegex(highlights), [highlights]);
@@ -214,7 +212,7 @@ export function SearchResultGroup({
             />
           </Avatar>
           <Text size="H4" truncate>
-            {localNames[room.roomId] ?? room.name}
+            {room.name}
           </Text>
         </Box>
       </Header>

src/app/features/room/RoomTimeline.tsx

@@ -121,7 +121,7 @@ import { ThreadSummary } from './thread/ThreadSummary';
 import { usePowerLevelsContext } from '../../hooks/usePowerLevels';
 import { GetContentCallback, MessageEvent, StateEvent } from '../../../types/matrix/room';
 import { useStateEvent } from '../../hooks/useStateEvent';
-import { RetentionContent, isExpired } from '../../utils/retention';
+import { RetentionContent, effectiveRetentionMs, isExpired } from '../../utils/retention';
 import { useKeyDown } from '../../hooks/useKeyDown';
 import { useDocumentFocusChange } from '../../hooks/useDocumentFocusChange';
 import { RenderMessageContent } from '../../components/RenderMessageContent';
@@ -494,7 +494,10 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
   // timeline (unless "show hidden events" is on). Reactive so a policy change
   // re-renders. `undefined` = no policy.
   const retentionEvent = useStateEvent(room, StateEvent.RoomRetention);
-  const retentionMs = retentionEvent?.getContent<RetentionContent>().max_lifetime;
+  // [Gitea #298] Same floor as everywhere else: a tiny value must not blank the room.
+  const retentionMs = effectiveRetentionMs(
+    retentionEvent?.getContent<RetentionContent>().max_lifetime,
+  );
   const [showDeveloperTools] = useSetting(settingsAtom, 'developerTools');
   const [lotusTerminal] = useSetting(settingsAtom, 'lotusTerminal');
 

src/app/features/room/thread/ThreadPanel.tsx

@@ -32,7 +32,6 @@ import { useThreadNotificationMode } from '../../../hooks/useThreadNotifications
 import { useTimestampFormatter } from '../../../hooks/useTimestampFormatter';
 import { getMemberName } from '../../../utils/room';
 import { ThreadNotificationMode } from '../../../utils/threadNotifications';
-import { useLocalRoomNames } from '../../../hooks/useRoomMeta';
 
 type ThreadPanelHeaderProps = {
   room: Room;
@@ -40,7 +39,6 @@ type ThreadPanelHeaderProps = {
   requestClose: () => void;
 };
 function ThreadPanelHeader({ room, threadId, requestClose }: ThreadPanelHeaderProps) {
-  const localNames = useLocalRoomNames();
   const mode = useThreadNotificationMode(room.roomId, threadId);
   const { format } = useTimestampFormatter();
   // [Gitea #165] Who started the thread and when — the first thing you want
@@ -57,7 +55,7 @@ function ThreadPanelHeader({ room, threadId, requestClose }: ThreadPanelHeaderPr
             Thread
           </Text>
           <Text size="T200" truncate style={{ opacity: 0.65 }}>
-            {localNames[room.roomId] ?? room.name}
+            {room.name}
             {startedBy && root && ` · started by ${startedBy}, ${format(root.getTs())}`}
           </Text>
         </Box>

src/app/features/room/thread/ThreadsListPanel.tsx

@@ -48,7 +48,6 @@ import { useTimestampFormatter } from '../../../hooks/useTimestampFormatter';
 import { formatRelativeAge } from '../../../utils/formatTimestamp';
 import { useRoomNavigate } from '../../../hooks/useRoomNavigate';
 import { ScreenSize, useScreenSizeContext } from '../../../hooks/useScreenSize';
-import { useLocalRoomNames } from '../../../hooks/useRoomMeta';
 
 // Persisted across panel opens (the panel unmounts on close). getOnInit reads
 // localStorage synchronously so the chosen filter/sort apply on first render.
@@ -236,7 +235,6 @@ export type ThreadsListPanelProps = {
   onOpenThread: (threadId: string) => void;
 };
 export function ThreadsListPanel({ room, onClose, onOpenThread }: ThreadsListPanelProps) {
-  const localNames = useLocalRoomNames();
   const { navigateRoom } = useRoomNavigate();
   const screenSize = useScreenSizeContext();
   const handleJump = useCallback(
@@ -363,7 +361,7 @@ export function ThreadsListPanel({ room, onClose, onOpenThread }: ThreadsListPan
               Threads
             </Text>
             <Text size="T200" truncate style={{ opacity: 0.65 }}>
-              {localNames[room.roomId] ?? room.name}
+              {room.name}
             </Text>
           </Box>
           {totalUnread > 0 && (

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -68,7 +68,12 @@ import { setPresenceWithRetry } from '../../utils/presenceWrite';
 import { useDeepLinkNavigate } from '../../hooks/useDeepLinkNavigate';
 import { dismissToastAtom, toastQueueAtom } from '../../state/toast';
 import { useReminders } from '../../hooks/useReminders';
-import { getRoomRetentionMs, isExpired } from '../../utils/retention';
+import {
+  getRoomRetentionMs,
+  getRoomRetentionSetAt,
+  isExpired,
+  retentionDeletesAllowed,
+} from '../../utils/retention';
 import { useTauriUpdateProgress, useTauriUpdater } from '../../hooks/useTauriUpdater';
 import { settingsRequestAtom } from '../../state/settingsRequest';
 import { isNetworkUpdateError } from '../../utils/updateErrors';
@@ -910,6 +915,9 @@ function RetentionSweeper() {
       mx.getRooms().forEach((room) => {
         const maxLifetime = getRoomRetentionMs(room);
         if (!maxLifetime) return;
+        // [Gitea #298] Never delete under a policy that is less than a day old.
+        const setAt = getRoomRetentionSetAt(room);
+        if (setAt === undefined || !retentionDeletesAllowed(setAt, now)) return;
         room
           .getLiveTimeline()
           .getEvents()

src/app/pages/client/inbox/Notifications.tsx

@@ -98,7 +98,6 @@ import { useRoomCreatorsTag } from '../../../hooks/useRoomCreatorsTag';
 import { useRoomCreators } from '../../../hooks/useRoomCreators';
 import { PresenceRingAvatar } from '../../../components/presence';
 import { AvatarDecoration } from '../../../components/avatar-decoration/AvatarDecoration';
-import { useLocalRoomNames } from '../../../hooks/useRoomMeta';
 
 type RoomNotificationsGroup = {
   roomId: string;
@@ -224,7 +223,6 @@ function RoomNotificationsGroupComp({
   hour24Clock,
   dateFormatString,
 }: RoomNotificationsGroupProps) {
-  const localNames = useLocalRoomNames();
   const mx = useMatrixClient();
   const useAuthentication = useMediaAuthentication();
   const unread = useRoomUnread(room.roomId, roomToUnreadAtom);
@@ -430,7 +428,7 @@ function RoomNotificationsGroupComp({
             />
           </Avatar>
           <Text size="H4" truncate>
-            {localNames[room.roomId] ?? room.name}
+            {room.name}
           </Text>
         </Box>
         <Box shrink="No">

src/app/utils/retention.test.ts

@@ -1,6 +1,13 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { isExpired, RETENTION_PRESETS, RETENTION_MIN_MS } from './retention';
+import {
+  effectiveRetentionMs,
+  isExpired,
+  RETENTION_DELETE_GRACE_MS,
+  RETENTION_MIN_MS,
+  RETENTION_PRESETS,
+  retentionDeletesAllowed,
+} from './retention';
 
 // MSC1763 retention: `isExpired` decides whether a message is past the room's
 // retention window. It must be strict (> window, not >=) and a disabled policy
@@ -40,3 +47,22 @@ test('presets: Off is 0 and the rest are strictly increasing, all >= the floor',
     'all presets above the floor',
   );
 });
+
+test('effectiveRetentionMs: tiny or invalid windows count as off (#298)', () => {
+  assert.equal(effectiveRetentionMs(1000), undefined, '1 s is a typo, not a policy');
+  assert.equal(effectiveRetentionMs(RETENTION_MIN_MS - 1), undefined);
+  assert.equal(effectiveRetentionMs(RETENTION_MIN_MS), RETENTION_MIN_MS);
+  assert.equal(effectiveRetentionMs(86_400_000), 86_400_000);
+  assert.equal(effectiveRetentionMs(0), undefined);
+  assert.equal(effectiveRetentionMs(-5), undefined);
+  assert.equal(effectiveRetentionMs('86400000'), undefined);
+  assert.equal(effectiveRetentionMs(Number.NaN), undefined);
+});
+
+test('retentionDeletesAllowed: no deletions in the first 24 h of a policy (#298)', () => {
+  const now = 1_000 * HOUR;
+  assert.equal(retentionDeletesAllowed(now - 2 * HOUR, now), false);
+  assert.equal(retentionDeletesAllowed(now - RETENTION_DELETE_GRACE_MS + 1, now), false);
+  assert.equal(retentionDeletesAllowed(now - RETENTION_DELETE_GRACE_MS, now), true);
+  assert.equal(retentionDeletesAllowed(now - 72 * HOUR, now), true);
+});

src/app/utils/retention.ts

@@ -20,13 +20,38 @@ export const RETENTION_PRESETS: RetentionPreset[] = [
   { label: '1 Month', ms: 30 * DAY_MS },
 ];
 
+/**
+ * [Gitea #298] A usable retention window, or `undefined`. Anything under
+ * RETENTION_MIN_MS is treated as off: a fat-fingered `max_lifetime: 1000` (set
+ * from any client by anyone with state power) used to blank every timeline and
+ * get opted-in users' messages redacted within a minute.
+ */
+export const effectiveRetentionMs = (maxLifetime: unknown): number | undefined =>
+  typeof maxLifetime === 'number' && Number.isFinite(maxLifetime) && maxLifetime >= RETENTION_MIN_MS
+    ? maxLifetime
+    : undefined;
+
 /** The room's active retention window in ms, or `undefined` when unset/disabled. */
 export const getRoomRetentionMs = (room: Room): number | undefined => {
   const event = room.currentState.getStateEvents(StateEvent.RoomRetention, '');
-  const ms = event?.getContent<RetentionContent>()?.max_lifetime;
-  return typeof ms === 'number' && ms > 0 ? ms : undefined;
+  return effectiveRetentionMs(event?.getContent<RetentionContent>()?.max_lifetime);
 };
 
+/**
+ * [Gitea #298] Deletion grace: the auto-delete sweeper ignores a retention
+ * policy for this long after it was set, so a mistaken or malicious change can
+ * be reverted before anything is permanently redacted. (Hiding expired
+ * messages locally is not destructive and applies at once.)
+ */
+export const RETENTION_DELETE_GRACE_MS = DAY_MS;
+
+export const retentionDeletesAllowed = (policySetAtMs: number, nowMs: number): boolean =>
+  nowMs - policySetAtMs >= RETENTION_DELETE_GRACE_MS;
+
+/** When the room's current retention policy was set (its state event's ts). */
+export const getRoomRetentionSetAt = (room: Room): number | undefined =>
+  room.currentState.getStateEvents(StateEvent.RoomRetention, '')?.getTs();
+
 /** True when an event at `tsMs` has passed the `maxLifetimeMs` retention window. */
 export const isExpired = (tsMs: number, maxLifetimeMs: number, nowMs: number): boolean =>
   maxLifetimeMs > 0 && nowMs - tsMs > maxLifetimeMs;