fix(calls): the call-failed screen gets a Try again button (#301)

"The call failed to load… try again" only offered Back, so the user had
to back out and press Join again. Try again starts a fresh embed for
the same room with the same mic/camera/sound (which disposes the hung
one); Back stays as the secondary action.

Fixes #301

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

src/app/features/call/CallView.tsx

@@ -6,12 +6,13 @@ import {
   useCallJoined,
   useCallEmbedPlacementSync,
   useCallLoadError,
+  useCallStart,
 } from '../../hooks/useCallEmbed';
 import { callEmbedAtom } from '../../state/callEmbed';
 import { ContainerColor } from '../../styles/ContainerColor.css';
 import { PrescreenControls } from './PrescreenControls';
 import { usePowerLevelsContext } from '../../hooks/usePowerLevels';
-import { useRoom } from '../../hooks/useRoom';
+import { useIsDirectRoom, useRoom } from '../../hooks/useRoom';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
 import { useRoomPermissions } from '../../hooks/useRoomPermissions';
 import { useMatrixClient } from '../../hooks/useMatrixClient';
@@ -160,6 +161,16 @@ function CallLoadErrorMessage() {
   // prescreen, where they can choose to join again.
   const dismiss = () => setCallEmbed(undefined);
 
+  // [Gitea #301] Try again: start a fresh embed for the same room with the
+  // same mic/camera/sound choices (starting one disposes the hung one).
+  const callEmbed = useCallEmbed();
+  const startCall = useCallStart(useIsDirectRoom());
+  const retry = () => {
+    if (!callEmbed) return;
+    const { room, control } = callEmbed;
+    startCall(room, { microphone: control.microphone, video: control.video, sound: control.sound });
+  };
+
   return (
     <Box
       className={css.CallViewContent}
@@ -173,6 +184,9 @@ function CallLoadErrorMessage() {
         The call failed to load. Check your connection and try again.
       </Text>
       <Box gap="200" alignItems="Center">
+        <Button variant="Primary" size="300" radii="400" onClick={retry} disabled={!callEmbed}>
+          <Text size="B400">Try again</Text>
+        </Button>
         <Button variant="Secondary" fill="Soft" size="300" radii="400" onClick={dismiss}>
           <Text size="B400">Back</Text>
         </Button>

src/app/plugins/call/CallWidgetDriver.ts

@@ -28,10 +28,7 @@ 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>;
 
@@ -132,18 +129,8 @@ 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.restartOnce(delayId, () =>
-      this.mx._unstable_restartScheduledDelayedEvent(delayId, {
-        localTimeoutMs: RESTART_TIMEOUT_MS,
-      }),
-    );
+    await this.mx._unstable_restartScheduledDelayedEvent(delayId);
   }
 
   public async sendScheduledDelayedEvent(delayId: string): Promise<void> {

src/app/utils/inFlight.test.ts

@@ -1,32 +0,0 @@
-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

@@ -1,14 +0,0 @@
-/**
- * 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;
-  };
-}