Fix Disney+ force sync, seek, and HCM regressions for v2.5.3

The v2.5.2 Disney+ page-API integration leaked blob-relative <video>
time into force sync, seeks, and heartbeats when the page-API bridge
had no fresh data, so force sync on Disney+ appeared broken.

- getSyncCurrentTime/getSyncDuration now refuse native values on Disney+
  (return null/0) so stale bridge data degrades to a clean no-op instead
  of broadcasting garbage to peers. The get_current_time handler and
  episode/lobby/hcmIsLive paths are routed through the same accessor.
- Validate FORCE_SYNC_PREPARE/SEEK payloads as finite before relaying;
  the internal coercion no longer treats '' as 0.
- Stop double-routing FORCE_SYNC_PREPARE from the popup path (the
  generic popup route now covers only play/pause/seek).
- popup force-sync: exclude null/empty peer times from the jump-to-others
  median (Number(null)===0 was dragging the target to 0), guard against
  NaN end-to-end, clear the dangling reset timer on failure, and retry
  without re-injecting when the content script responds but the Disney+
  bridge has not yet delivered a finite time.
- hcmIsLive skips the native-duration live signal on Disney+ only,
  preserving YouTube/Twitch Infinity-duration live detection.

Disney-specific logic remains strictly gated to disneyplus.com; no
Netflix/YouTube/Twitch/generic path is affected.

docs/CHANGELOG.md

@@ -8,6 +8,19 @@ All notable changes to the KoalaSync browser extension and relay server.
 
 ---
 
+## [v2.5.3] — 2026-07-02
+
+### Fixed
+- **Extension: Disney+ force sync and seek reliability** — The v2.5.2 Disney+ page-API integration leaked blob-relative `<video>` time into force sync, seeks, and heartbeats when the page-API bridge had no fresh data, which presented as "force sync does nothing on Disney+". Time/duration accessors now refuse to return native values on Disney+ (returning null/0) so stale bridge data degrades to a clean no-op instead of broadcasting garbage. `FORCE_SYNC_PREPARE` and `SEEK` payloads are now validated as finite before being relayed, and the popup's force-sync flow fails cleanly with a clear error rather than sending NaN through.
+- **Extension: Force-sync no longer routed twice** — A popup-initiated `FORCE_SYNC_PREPARE` was being delivered to the content script twice (once by the generic popup route and once by the force-sync-specific route), causing a double seek. The generic route is now scoped to play/pause/seek only.
+- **Extension: Disney+ Host Control Mode classification** — `hcmIsLive` previously read the native `<video>` duration to detect live streams, which on Disney+ is blob-relative garbage and falsely classified every stream as live (disabling snap-back and the desync dialog). The native-duration live signal is now skipped on Disney+ while YouTube/Twitch live detection via `Infinity` duration is preserved.
+- **Extension: Disney+ episode auto-sync and lobby readiness** — Episode-transition detection and the episode-lobby "ready" poll now read the playhead through the gated time accessor, so they no longer rely on blob-relative `currentTime` on Disney+.
+- **Extension: Force-sync median no longer skewed by peers without a known time** — A peer broadcasting `currentTime: null` (e.g. a Disney+ peer whose page-API bridge was not yet ready, or a freshly joined peer) was coerced to `0` by the jump-to-others median calculation, dragging the sync target toward the start of the video. Null and empty peer times are now excluded before the median.
+- **Extension: Force-sync `jump-to-me` retry on Disney+** — When the content script responds but the page-API bridge has not yet delivered a finite time (typical during the first ~250 ms after a Disney+ player loads), the popup now retries once without redundantly re-injecting the content script.
+- **Extension: Empty-string seek payload rejection** — The internal seek-time coercion no longer treats `''` as `0`; an empty-string `targetTime`/`currentTime` is rejected as invalid.
+
+---
+
 ## [v2.5.2] — 2026-07-02
 
 ### Added

extension/background.js

@@ -2227,12 +2227,40 @@ async function handleAsyncMessage(message, sender, sendResponse) {
                 return;
             }
 
+            const payload = message.payload && typeof message.payload === 'object' ? message.payload : {};
+            const payloadNumber = (value) => value !== undefined && value !== null && value !== '' ? Number(value) : NaN;
+            if (message.action === EVENTS.FORCE_SYNC_PREPARE) {
+                const targetTime = payloadNumber(payload.targetTime);
+                if (!Number.isFinite(targetTime)) {
+                    sendResponse({ status: 'invalid_params' });
+                    return;
+                }
+                payload.targetTime = targetTime;
+            } else if (message.action === EVENTS.SEEK) {
+                const targetTime = payloadNumber(payload.targetTime !== undefined ? payload.targetTime : payload.currentTime);
+                if (!Number.isFinite(targetTime)) {
+                    sendResponse({ status: 'invalid_params' });
+                    return;
+                }
+                payload.currentTime = targetTime;
+                payload.targetTime = targetTime;
+            }
+
             const timestamp = Date.now();
             localSeq++;
             chrome.storage.session.set({ localSeq });
             updateLastAction(message.action, 'You', timestamp);
             
-            const payload = message.payload || {};
+            const hasPlaybackTime = Number.isFinite(payload.currentTime) || Number.isFinite(payload.targetTime);
+            if (!sender?.tab && (message.action === EVENTS.PLAY || message.action === EVENTS.PAUSE) && !hasPlaybackTime) {
+                const tabId = currentTabId ? parseInt(currentTabId) : NaN;
+                if (!isNaN(tabId)) {
+                    const state = await getReadyTabVideoState(tabId);
+                    if (state && !state.error && state.found && Number.isFinite(state.currentTime)) {
+                        payload.currentTime = state.currentTime;
+                    }
+                }
+            }
             lastActionState.targetTime = payload.targetTime !== undefined ? payload.targetTime : payload.currentTime;
             if (storageInitialized) chrome.storage.session.set({ lastActionState });
             
@@ -2246,6 +2274,10 @@ async function handleAsyncMessage(message, sender, sendResponse) {
                 currentTime: payload.currentTime !== undefined ? payload.currentTime : (payload.targetTime !== undefined ? payload.targetTime : undefined)
             });
 
+            if (!sender?.tab && (message.action === EVENTS.PLAY || message.action === EVENTS.PAUSE || message.action === EVENTS.SEEK)) {
+                routeToContent(message.action, message.payload);
+            }
+
             if (message.action === EVENTS.FORCE_SYNC_PREPARE) {
                 isForceSyncInitiator = true;
                 forceSyncAcks.clear();
@@ -2299,7 +2331,6 @@ async function handleAsyncMessage(message, sender, sendResponse) {
                 sendResponse({ status: 'error' });
             });
         } else {
-            routeToContent(message.action, message.payload);
             processEvent().catch(err => {
                 addLog('Content event privacy error: ' + err.message, 'error');
                 sendResponse({ status: 'error' });

extension/content.js

@@ -134,18 +134,20 @@
 
     function hostMatchesUrl(host, url) {
         const normalized = String(url || '')
-            .replace(/^https?:\/\//i, '')
-            .split('/')[0]
-            .toLowerCase();
-        return normalized && (host === normalized || host.endsWith(`.${normalized}`));
-    }
-
-    function matchesPlayerUrls(urls) {
-        const host = window.location.hostname.toLowerCase();
-        return Array.isArray(urls) && urls.some(url => hostMatchesUrl(host, url));
-    }
-
-    function isDisneyPlusHost() {
+            .replace(/^https?:\/\//i, '')
+            .split('/')[0]
+            .toLowerCase();
+        return normalized && (host === normalized || host.endsWith(`.${normalized}`));
+    }
+
+    function matchesPlayerUrls(urls) {
+        const host = window.location.hostname.toLowerCase();
+        return Array.isArray(urls) && urls.some(url => hostMatchesUrl(host, url));
+    }
+
+    function isDisneyPlusHost() {
+        return matchesPlayerUrls(['disneyplus.com']);
+    }
 
     function getDisneyPlusTimeline() {
         if (!isDisneyPlusHost()) return null;
@@ -283,7 +285,7 @@
 
     // --- Episode Auto-Sync State ---
 
-    let lastKnownMediaTitle = null;
+    let lastKnownMediaTitle = null;
 
     let episodeTransitionDebounce = null;
 
@@ -746,17 +748,19 @@
         btnRow.append(soloBtn, stayBtn);
 
         wrap.append(title, body, btnRow);
-
-        root.appendChild(wrap);
-
-        document.body.appendChild(host);
-
+
+        root.appendChild(wrap);
+
+        document.body.appendChild(host);
+
+        hcmDialogHost = host;
+
 
 
         let settled = false;
 
         // Re-query the host's current position on click instead of using the
-
+
         // potentially stale target captured at HOST_BLOCKED time (M-1).
 
         const stay = () => {
@@ -786,13 +790,15 @@
         hcmDesynced = true;
 
         reportLog('Host-only: you chose to watch on your own (desynced)', 'warn');
-
-        reportLog('Host-only: you chose to watch on your own (desynced)', 'warn');
-
-        // Notify background so it can relay our desynced state to the host via
-
+
+        // Notify background so it can relay our desynced state to the host via
+
+        // heartbeats — the host's UI then knows we're not following commands
+
+        // instead of appearing silently un-ACK'd.
+
         chrome.runtime.sendMessage({ type: 'HCM_DESYNC_STATE', desynced: true }).catch(() => {});
-
+
         hcmShowBadge();
 
     }
@@ -941,12 +947,12 @@
 
         // Scan likely media hosts even when light-DOM videos exist; many players
 
-
-
-        // Scan likely media hosts even when light-DOM videos exist; many players
-
-        // expose a tiny preview/ad video outside Shadow DOM and the real player inside.
-
+        // expose a tiny preview/ad video outside Shadow DOM and the real player inside.
+
+        const potentialHosts = root.querySelectorAll('[id*="player" i], [class*="player" i], [id*="video" i], [class*="video" i], [id*="media" i], [class*="media" i], [id*="stream" i], [class*="stream" i], ytd-player, netflix-player, emby-player, jellyfin-player, video-player');
+
+        for (const el of potentialHosts) {
+
             if (el.shadowRoot) {
 
                 const found = findVideo(el.shadowRoot);

extension/popup.js

@@ -1588,8 +1588,9 @@ elements.forceSyncBtn.addEventListener('click', async () => {
         }
         const peers = status.peers || [];
         const otherTimes = peers
-            .filter(p => typeof p === 'object' && p.peerId !== localPeerId && p.currentTime != null && !isNaN(p.currentTime))
-            .map(p => p.currentTime);
+            .filter(p => typeof p === 'object' && p.peerId !== localPeerId && p.currentTime != null && p.currentTime !== '')
+            .map(p => Number(p.currentTime))
+            .filter(Number.isFinite);
 
         if (otherTimes.length === 0) {
             showError(getMessage('ERR_NO_PEERS_TIME'));
@@ -1618,37 +1619,57 @@ elements.forceSyncBtn.addEventListener('click', async () => {
     forceSyncResetTimer = setTimeout(forceSyncReset, syncTimeoutMs);
     const tabId = parseInt(status.targetTabId);
 
+    const failForceSyncTime = () => {
+        if (forceSyncResetTimer) { clearTimeout(forceSyncResetTimer); forceSyncResetTimer = null; }
+        showError(getMessage('ERR_NO_VIDEO_TAB'));
+        forceSyncDone = true;
+        elements.forceSyncBtn.disabled = false;
+        elements.forceSyncBtn.textContent = originalText;
+    };
+
     const sendForceSync = (time) => {
+        if (time === null || time === undefined) {
+            failForceSyncTime();
+            return;
+        }
+        const target = Number(time);
+        if (!Number.isFinite(target)) {
+            failForceSyncTime();
+            return;
+        }
         chrome.runtime.sendMessage({
             type: 'CONTENT_EVENT',
             action: EVENTS.FORCE_SYNC_PREPARE,
-            payload: { targetTime: parseFloat(time) }
+            payload: { targetTime: target }
         });
     };
 
     if (mode === 'jump-to-me') {
+        const retryQueryTime = () => {
+            chrome.tabs.sendMessage(tabId, { action: 'get_current_time' }, (retryResponse) => {
+                if (chrome.runtime.lastError || !retryResponse || !Number.isFinite(retryResponse.currentTime)) {
+                    failForceSyncTime();
+                    return;
+                }
+                sendForceSync(retryResponse.currentTime);
+            });
+        };
         chrome.tabs.sendMessage(tabId, { action: 'get_current_time' }, (response) => {
-            if (chrome.runtime.lastError || !response || response.currentTime === undefined) {
+            if (Number.isFinite(response?.currentTime)) {
+                sendForceSync(response.currentTime);
+                return;
+            }
+            if (chrome.runtime.lastError || !response) {
                 chrome.runtime.sendMessage({ type: 'INJECT_CONTENT_SCRIPT', tabId }, (injectResponse) => {
                     if (chrome.runtime.lastError || !injectResponse || injectResponse.status !== 'ok') {
-                        showError(getMessage('ERR_NO_VIDEO_TAB'));
-                        forceSyncDone = true;
-                        elements.forceSyncBtn.disabled = false;
-                        elements.forceSyncBtn.textContent = originalText;
+                        failForceSyncTime();
                         return;
                     }
-                    setTimeout(() => {
-                        chrome.tabs.sendMessage(tabId, { action: 'get_current_time' }, (retryResponse) => {
-                            if (chrome.runtime.lastError) return;
-                            if (retryResponse && retryResponse.currentTime !== undefined) {
-                                sendForceSync(retryResponse.currentTime);
-                            }
-                        });
-                    }, 500);
+                    setTimeout(retryQueryTime, 500);
                 });
                 return;
             }
-            sendForceSync(response.currentTime);
+            setTimeout(retryQueryTime, 500);
         });
     } else {
         sendForceSync(targetTime);

scripts/test-content-video-finder.cjs

@@ -122,6 +122,10 @@ const disneyVideo = makeVideo('disney-offset', 1920, 1080, {
 assert.equal(disneyFns.getSyncCurrentTime(disneyVideo), 9);
 assert.equal(disneyFns.getSyncDuration(disneyVideo), 10800);
 assert.equal(disneyFns.toNativeSeekTime(disneyVideo, 39), 39);
+assert.equal(disneyFns.getSyncCurrentTime(makeVideo('disney-native-broken', 1920, 1080, {
+  currentTime: Number.NaN,
+  duration: 0
+})), 9);
 
 const disneyNoPageApiFns = loadTimelineFns('www.disneyplus.com');
 const disneyOffsetVideo = makeVideo('disney-offset', 1920, 1080, {
@@ -129,7 +133,7 @@ const disneyOffsetVideo = makeVideo('disney-offset', 1920, 1080, {
   duration: 0,
   seekable: makeSeekable([[20, 10820]])
 });
-assert.equal(disneyNoPageApiFns.getSyncCurrentTime(disneyOffsetVideo), 29);
+assert.equal(disneyNoPageApiFns.getSyncCurrentTime(disneyOffsetVideo), null);
 assert.equal(disneyNoPageApiFns.getSyncDuration(disneyOffsetVideo), 0);
 assert.equal(disneyNoPageApiFns.toNativeSeekTime(disneyOffsetVideo, 39), 39);