From 0c32fede2975481c70c3ede2bb31d96492c88ec3 Mon Sep 17 00:00:00 2001
From: zubiden <19638254+zubiden@users.noreply.github.com>
Date: Tue, 5 May 2026 13:46:25 +0200
Subject: [PATCH] Multitab: Force sync at least every 500ms (#6914)

---
 src/api/gramjs/methods/messages.ts | 28 ++++++++++++++++------
 src/util/browser/multitab.ts       | 37 ++++++++++++++++++++----------
 2 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/src/api/gramjs/methods/messages.ts b/src/api/gramjs/methods/messages.ts
index 912579259..318cca519 100644
--- a/src/api/gramjs/methods/messages.ts
+++ b/src/api/gramjs/methods/messages.ts
@@ -379,9 +379,10 @@ export function sendApiMessage(
 
   if (!chat) return undefined;
 
-  // This is expected to arrive after `updateMessageSendSucceeded` which replaces the local ID,
-  // so in most cases this will be simply ignored
+  let isSendCompleted = false;
   const timeout = setTimeout(() => {
+    if (isSendCompleted) return;
+
     sendApiUpdate({
       '@type': localMessage.isScheduled ? 'updateScheduledMessage' : 'updateMessage',
       id: localMessage.id,
@@ -392,6 +393,10 @@ export function sendApiMessage(
       isFull: false,
     });
   }, FAST_SEND_TIMEOUT);
+  const cancelSendingStatusTimeout = () => {
+    isSendCompleted = true;
+    clearTimeout(timeout);
+  };
 
   const randomId = generateRandomBigInt();
 
@@ -408,7 +413,7 @@ export function sendApiMessage(
       scheduledAt,
       scheduleRepeatPeriod,
       messagePriceInStars,
-    }, randomId, localMessage, onProgress);
+    }, randomId, localMessage, onProgress, cancelSendingStatusTimeout);
   }
 
   const messagePromise = (async () => {
@@ -564,8 +569,11 @@ export function sendApiMessage(
         });
       }
 
+      cancelSendingStatusTimeout();
       if (update) handleLocalMessageUpdate(localMessage, update);
     } catch (error: any) {
+      cancelSendingStatusTimeout();
+
       if (error.errorMessage === 'PRIVACY_PREMIUM_REQUIRED') {
         sendApiUpdate({ '@type': 'updateRequestUserUpdate', id: chat.id });
       }
@@ -576,7 +584,6 @@ export function sendApiMessage(
         localId: localMessage.id,
         error: error.errorMessage,
       });
-      clearTimeout(timeout);
     }
   })();
 
@@ -595,6 +602,7 @@ const groupedUploads: Record<string, {
   counter: number;
   singleMediaByIndex: Record<number, GramJs.InputSingleMedia>;
   localMessages: Record<string, ApiMessage>;
+  cancelSendingStatusTimeouts: Record<string, NoneToVoidFunction>;
 }> = {};
 
 function sendGroupedMedia(
@@ -627,7 +635,8 @@ function sendGroupedMedia(
   },
   randomId: GramJs.long,
   localMessage: ApiMessage,
-  onProgress?: ApiOnProgress,
+  onProgress: ApiOnProgress | undefined,
+  cancelSendingStatusTimeout: NoneToVoidFunction,
 ) {
   let groupIndex = -1;
   if (!groupedUploads[groupedId]) {
@@ -635,6 +644,7 @@ function sendGroupedMedia(
       counter: 0,
       singleMediaByIndex: {},
       localMessages: {},
+      cancelSendingStatusTimeouts: {},
     };
   }
 
@@ -689,12 +699,13 @@ function sendGroupedMedia(
       entities: entities ? entities.map(buildMtpMessageEntity) : undefined,
     });
     groupedUploads[groupedId].localMessages[randomId.toString()] = localMessage;
+    groupedUploads[groupedId].cancelSendingStatusTimeouts[randomId.toString()] = cancelSendingStatusTimeout;
 
     if (Object.keys(groupedUploads[groupedId].singleMediaByIndex).length < groupedUploads[groupedId].counter) {
       return;
     }
 
-    const { singleMediaByIndex, localMessages } = groupedUploads[groupedId];
+    const { singleMediaByIndex, localMessages, cancelSendingStatusTimeouts } = groupedUploads[groupedId];
     delete groupedUploads[groupedId];
     const count = Object.values(singleMediaByIndex).length;
 
@@ -713,7 +724,10 @@ function sendGroupedMedia(
       shouldIgnoreUpdates: true,
     });
 
-    if (update) handleMultipleLocalMessagesUpdate(localMessages, update);
+    if (!update) return;
+
+    Object.values(cancelSendingStatusTimeouts).forEach((cancel) => cancel());
+    handleMultipleLocalMessagesUpdate(localMessages, update);
   })();
 
   return mediaQueue;
diff --git a/src/util/browser/multitab.ts b/src/util/browser/multitab.ts
index c83f2f2b0..d9663db17 100644
--- a/src/util/browser/multitab.ts
+++ b/src/util/browser/multitab.ts
@@ -94,6 +94,7 @@ type BroadcastChannelInitApi = {
 };
 
 const MULTITAB_ESTABLISH_TIMEOUT = 800;
+const BROADCAST_DIFF_FALLBACK_TIMEOUT = 500;
 
 export type TypedBroadcastChannel = {
   postMessage: (message: BroadcastChannelMessage) => void;
@@ -117,6 +118,28 @@ const channel = new BroadcastChannel(DATA_BROADCAST_CHANNEL_NAME) as TypedBroadc
 
 let isBroadcastDiffScheduled = false;
 let lastBroadcastDiffGlobal: GlobalState | undefined;
+let broadcastDiffFallbackTimeout: number | undefined;
+
+function flushBroadcastDiff() {
+  if (!isBroadcastDiffScheduled) return;
+
+  if (broadcastDiffFallbackTimeout) {
+    clearTimeout(broadcastDiffFallbackTimeout);
+    broadcastDiffFallbackTimeout = undefined;
+  }
+
+  const diff = deepDiff(lastBroadcastDiffGlobal, currentGlobal);
+
+  if (typeof diff !== 'symbol') {
+    channel.postMessage({
+      type: 'globalDiffUpdate',
+      diff,
+    });
+  }
+
+  isBroadcastDiffScheduled = false;
+  lastBroadcastDiffGlobal = undefined;
+}
 
 function broadcastDiffOnIdle() {
   if (isBroadcastDiffScheduled) return;
@@ -124,18 +147,8 @@ function broadcastDiffOnIdle() {
   isBroadcastDiffScheduled = true;
   lastBroadcastDiffGlobal = currentGlobal;
 
-  onFullyIdle(() => {
-    const diff = deepDiff(lastBroadcastDiffGlobal, currentGlobal);
-
-    if (typeof diff !== 'symbol') {
-      channel.postMessage({
-        type: 'globalDiffUpdate',
-        diff,
-      });
-    }
-
-    isBroadcastDiffScheduled = false;
-  });
+  onFullyIdle(flushBroadcastDiff);
+  broadcastDiffFallbackTimeout = window.setTimeout(flushBroadcastDiff, BROADCAST_DIFF_FALLBACK_TIMEOUT);
 }
 
 export function unsubcribeFromMultitabBroadcastChannel() {