fix(calls): one delayed-event restart in flight per id, with a timeout (#318)

During a homeserver stall Element Call retries update_delayed_event every
2 s, and the host opened a new HTTP request each time: 12 pending in a
60 s stall, all landing together on recovery (404 x5, 429 x7). Share the
in-flight restart per delay id and abort it after 5 s.

Refs #318

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

src/app/components/AccountDataEditor.tsx

@@ -297,7 +297,7 @@ export function AccountDataEditor({
             </Chip>
           </Box>
           <Box shrink="No">
-            <IconButton type="button" onClick={requestClose} variant="Surface" aria-label="Close">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/components/CallEmbedProvider.tsx

@@ -111,8 +111,6 @@ type IncomingCallInfo = {
   intent?: string;
   notificationType: RTCNotificationType;
   refEventId: string;
-  /** [Gitea #313] The rtc.notification event itself: what a decline must reference (MSC4310). */
-  notificationEventId?: string;
 };
 type IncomingCallProps = {
   dm: boolean;
@@ -285,9 +283,7 @@ function IncomingCall({ dm, info, onIgnore, onAnswer, onReject }: IncomingCallPr
                   fill="Soft"
                   size="400"
                   radii="400"
-                  onClick={() =>
-                    dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-                  }
+                  onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
                   before={<Icon size="200" src={Icons.Cross} filled />}
                 >
                   <Text as="span" size="B400">
@@ -459,9 +455,7 @@ function IncomingCallBanner({ dm, info, onIgnore, onAnswer, onReject }: Incoming
           size="300"
           radii="300"
           outlined
-          onClick={() =>
-            dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-          }
+          onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
           before={<Icon size="100" src={Icons.Cross} filled />}
         >
           <Text as="span" size="B300">
@@ -602,7 +596,6 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
             : undefined,
         notificationType,
         refEventId,
-        notificationEventId: event.getId(),
       };
 
       // [Gitea #312] Don't ring for a call that is already over or handled: after
@@ -611,10 +604,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       // stale RTC session). The caller's membership can arrive just after the
       // ring, so an absent one gets a short grace period before giving up.
       const myUserId = mx.getSafeUserId();
-      if (
-        declinedRing(room, [refEventId, event.getId()], myUserId) ||
-        hasActiveCallMembership(room, myUserId)
-      ) {
+      if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
         return;
       }
       if (hasActiveCallMembership(room, sender)) {
@@ -623,10 +613,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       }
       setTimeout(() => {
         if (Date.now() >= senderTs + lifetime) return;
-        if (
-          declinedRing(room, [refEventId, event.getId()], myUserId) ||
-          hasActiveCallMembership(room, myUserId)
-        ) {
+        if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
           return;
         }
         if (hasActiveCallMembership(room, sender)) setCallInfo(info);
@@ -698,10 +685,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       if (eventRoom?.roomId !== room.roomId || !data.liveEvent) return;
       if (event.getType() === EventType.RTCDecline && event.getSender() === myUserId) {
         const related = event.getRelation()?.event_id;
-        // [Gitea #313] Correct clients reference the notification; older Lotus
-        // builds referenced the call membership. Accept both.
-        if (!related || related === refEventId || related === callInfo.notificationEventId)
-          dismiss(); // declined elsewhere
+        if (!related || related === refEventId) dismiss(); // declined elsewhere
       }
     };
     session.on(MatrixRTCSessionEvent.MembershipsChanged, checkMemberships);

src/app/components/DeviceVerificationSetup.tsx

@@ -315,7 +315,7 @@ export const DeviceVerificationSetup = forwardRef<HTMLDivElement, DeviceVerifica
               Setup Device Verification
             </Text>
           </Box>
-          <IconButton type="button" size="300" radii="300" onClick={onCancel} aria-label="Cancel">
+          <IconButton size="300" radii="300" onClick={onCancel} aria-label="Cancel">
             <Icon src={Icons.Cross} />
           </IconButton>
         </Header>
@@ -361,7 +361,7 @@ export const DeviceVerificationReset = forwardRef<HTMLDivElement, DeviceVerifica
               Reset Device Verification
             </Text>
           </Box>
-          <IconButton type="button" size="300" radii="300" onClick={onCancel} aria-label="Cancel">
+          <IconButton size="300" radii="300" onClick={onCancel} aria-label="Cancel">
             <Icon src={Icons.Cross} />
           </IconButton>
         </Header>

src/app/features/common-settings/developer-tools/StateEventEditor.tsx

@@ -275,7 +275,7 @@ export function StateEventEditor({ type, stateKey, requestClose }: StateEventEdi
             </Chip>
           </Box>
           <Box shrink="No">
-            <IconButton type="button" onClick={requestClose} variant="Surface" aria-label="Close">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/features/room/PollCreator.tsx

@@ -143,7 +143,7 @@ export function PollCreator({ roomId, threadRootId, onClose }: PollCreatorProps)
                   Create Poll
                 </Text>
               </Box>
-              <IconButton type="button" size="300" radii="300" onClick={onClose} aria-label="Close">
+              <IconButton size="300" radii="300" onClick={onClose} aria-label="Close">
                 <Icon src={Icons.Cross} />
               </IconButton>
             </Header>

src/app/features/room/ReportRoomModal.tsx

@@ -118,7 +118,7 @@ export function ReportRoomModal({ roomId, onClose }: ReportRoomModalProps) {
                   Report Room
                 </Text>
               </Box>
-              <IconButton type="button" size="300" onClick={onClose} radii="300" aria-label="Close">
+              <IconButton size="300" onClick={onClose} radii="300" aria-label="Close">
                 <Icon src={Icons.Cross} />
               </IconButton>
             </Header>

src/app/features/room/ReportUserModal.tsx

@@ -124,7 +124,7 @@ export function ReportUserModal({ userId, onClose }: ReportUserModalProps) {
                   Report User
                 </Text>
               </Box>
-              <IconButton type="button" size="300" onClick={onClose} radii="300" aria-label="Close">
+              <IconButton size="300" onClick={onClose} radii="300" aria-label="Close">
                 <Icon src={Icons.Cross} />
               </IconButton>
             </Header>

src/app/features/room/RoomTimeline.tsx

@@ -138,7 +138,7 @@ import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { useIgnoredUsers } from '../../hooks/useIgnoredUsers';
 import { useImagePackRooms } from '../../hooks/useImagePackRooms';
 import { useIsDirectRoom } from '../../hooks/useRoom';
-import { declinedRing, isRingableRoom } from '../../utils/callRing';
+import { isRingableRoom } from '../../utils/callRing';
 import { useOpenUserRoomProfile } from '../../state/hooks/userRoomProfile';
 import { useSpaceOptionally } from '../../hooks/useSpace';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
@@ -2037,9 +2037,6 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         // Same rule as ringing: no "Missed call" in voice rooms or space
         // channels, where starting a call is just joining the channel.
         if (!isRingableRoom(room, direct)) return null;
-        // [Gitea #313] A call we declined isn't a missed call.
-        const ringRef = mEvent.getRelation()?.event_id;
-        if (declinedRing(room, [mEventId, ringRef], mx.getSafeUserId())) return null;
         const content = mEvent.getContent();
         const mention =
           content['m.mentions']?.room ||

src/app/features/room/ScheduleMessageModal.tsx

@@ -202,7 +202,7 @@ export function ScheduleMessageModal({
                   {title}
                 </Text>
               </Box>
-              <IconButton type="button" size="300" radii="300" onClick={onClose} aria-label="Close">
+              <IconButton size="300" radii="300" onClick={onClose} aria-label="Close">
                 <Icon src={Icons.Cross} />
               </IconButton>
             </Header>

src/app/features/room/message/Message.tsx

@@ -725,13 +725,7 @@ export const MessageDeleteItem = as<
                     Delete Message
                   </Text>
                 </Box>
-                <IconButton
-                  type="button"
-                  size="300"
-                  onClick={handleClose}
-                  radii="300"
-                  aria-label="Close"
-                >
+                <IconButton size="300" onClick={handleClose} radii="300" aria-label="Close">
                   <Icon src={Icons.Cross} />
                 </IconButton>
               </Header>
@@ -871,13 +865,7 @@ export const MessageReportItem = as<
                     Report Message
                   </Text>
                 </Box>
-                <IconButton
-                  type="button"
-                  size="300"
-                  onClick={handleClose}
-                  radii="300"
-                  aria-label="Close"
-                >
+                <IconButton size="300" onClick={handleClose} radii="300" aria-label="Close">
                   <Icon src={Icons.Cross} />
                 </IconButton>
               </Header>

src/app/plugins/call/CallWidgetDriver.ts

@@ -28,7 +28,10 @@ import {
 } from 'matrix-js-sdk';
 import { getCallCapabilities } from './utils';
 import { downloadMedia, mxcUrlToHttp } from '../../utils/matrix';
+import { dedupeInFlight } from '../../utils/inFlight';
 
+/** A little longer than Element Call's own 2 s timeout for a restart. */
+const RESTART_TIMEOUT_MS = 5000;
 export class CallWidgetDriver extends WidgetDriver {
   private allowedCapabilities: Set<Capability>;
 
@@ -129,8 +132,18 @@ export class CallWidgetDriver extends WidgetDriver {
     await this.mx._unstable_cancelScheduledDelayedEvent(delayId);
   }
 
+  // [Gitea #318] While the homeserver is stalled, Element Call times out each
+  // restart locally after 2 s and asks again, so requests for the same delay
+  // id piled up and hit the server together on recovery (404s, then 429s).
+  // Share one in-flight restart per id, and give it a timeout of its own.
+  private readonly restartOnce = dedupeInFlight<unknown>();
+
   public async restartScheduledDelayedEvent(delayId: string): Promise<void> {
-    await this.mx._unstable_restartScheduledDelayedEvent(delayId);
+    await this.restartOnce(delayId, () =>
+      this.mx._unstable_restartScheduledDelayedEvent(delayId, {
+        localTimeoutMs: RESTART_TIMEOUT_MS,
+      }),
+    );
   }
 
   public async sendScheduledDelayedEvent(delayId: string): Promise<void> {

src/app/utils/callRing.test.ts

@@ -67,18 +67,3 @@ test('declinedRing finds our own decline of that ring only (#312)', () => {
   assert.equal(declinedRing(room, '$ring2', '@me:x'), false, "someone else's decline");
   assert.equal(declinedRing(room, '$ring3', '@me:x'), false);
 });
-
-test('declinedRing matches a decline of the notification or of the membership (#313)', () => {
-  const decline = (rel: string) => ({
-    getType: () => 'org.matrix.msc4310.rtc.decline',
-    getSender: () => '@me:x',
-    getRelation: () => ({ event_id: rel }),
-  });
-  const room = stateRoom([], [decline('$notification')]);
-  assert.equal(declinedRing(room, ['$membership', '$notification'], '@me:x'), true);
-  assert.equal(declinedRing(room, ['$membership'], '@me:x'), false);
-  assert.equal(
-    declinedRing(stateRoom([], [decline('$membership')]), ['$membership', undefined], '@me:x'),
-    true,
-  );
-});

src/app/utils/callRing.ts

@@ -40,18 +40,7 @@ export const hasActiveCallMembership = (room: Room, userId: string): boolean =>
  * declined it (our own RTCDecline relates to it) — e.g. replayed together with
  * the ring in the first sync after a restart, before any dismiss listener.
  */
-export const declinedRing = (
-  room: Room,
-  ringIds: string | Array<string | undefined>,
-  myUserId: string,
-): boolean => {
-  // [Gitea #313] A decline references the notification event (MSC4310); older
-  // Lotus builds referenced the call membership instead. Match either.
-  const ids = new Set((Array.isArray(ringIds) ? ringIds : [ringIds]).filter(Boolean));
-  return declinedAny(room, ids, myUserId);
-};
-
-const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string): boolean =>
+export const declinedRing = (room: Room, refEventId: string, myUserId: string): boolean =>
   room
     .getLiveTimeline()
     .getEvents()
@@ -59,5 +48,5 @@ const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string)
       (ev) =>
         ev.getType() === 'org.matrix.msc4310.rtc.decline' &&
         ev.getSender() === myUserId &&
-        ids.has(ev.getRelation()?.event_id),
+        ev.getRelation()?.event_id === refEventId,
     );

src/app/utils/inFlight.test.ts

@@ -0,0 +1,32 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { dedupeInFlight } from './inFlight';
+
+test('dedupeInFlight: one request per key while pending, a new one after (#318)', async () => {
+  const once = dedupeInFlight<number>();
+  let calls = 0;
+  let release!: () => void;
+  const gate = new Promise<void>((r) => {
+    release = r;
+  });
+  const run = async () => {
+    calls += 1;
+    await gate;
+    return calls;
+  };
+  const a = once('d1', run);
+  const b = once('d1', run);
+  const c = once('d2', run);
+  assert.equal(a, b);
+  release();
+  assert.deepEqual(await Promise.all([a, b, c]), [2, 2, 2]);
+  assert.equal(calls, 2);
+  await once('d1', run);
+  assert.equal(calls, 3, 'settled requests are not reused');
+});
+
+test('dedupeInFlight: a rejection clears the key', async () => {
+  const once = dedupeInFlight<void>();
+  await assert.rejects(once('k', () => Promise.reject(new Error('boom'))));
+  await once('k', () => Promise.resolve());
+});

src/app/utils/inFlight.ts

@@ -0,0 +1,14 @@
+/**
+ * Share one in-flight promise per key: callers that ask again while a request
+ * for the same key is still pending get that request instead of a new one.
+ */
+export function dedupeInFlight<T>(): (key: string, run: () => Promise<T>) => Promise<T> {
+  const pending = new Map<string, Promise<T>>();
+  return (key, run) => {
+    const existing = pending.get(key);
+    if (existing) return existing;
+    const p = run().finally(() => pending.delete(key));
+    pending.set(key, p);
+    return p;
+  };
+}