From 0960c0dfeaa4ee6a51f07386604c5a9c623e41b7 Mon Sep 17 00:00:00 2001
From: Alex Hart <alex@signal.org>
Date: Thu, 7 May 2026 15:58:26 -0300
Subject: [PATCH] Skip processing backfill requests on linked devices.

---
 .../thoughtcrime/securesms/messages/SyncMessageProcessor.kt  | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt b/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
index 7c3c226b5c..31ee162a51 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
@@ -1680,6 +1680,11 @@ object SyncMessageProcessor {
   }
 
   private fun handleSynchronizeAttachmentBackfillRequest(request: SyncMessage.AttachmentBackfillRequest, timestamp: Long) {
+    if (SignalStore.account.isLinkedDevice) {
+      log(timestamp, "[AttachmentBackfillRequest] Linked device ignores attachment backfill request.")
+      return
+    }
+
     if (request.targetMessage == null || request.targetConversation == null) {
       warn(timestamp, "[AttachmentBackfillRequest] Target message or target conversation was unset! Can't formulate a response, ignoring.")
       return