fix: use dedicated ID for sync messages affecting device chat

Otherwise `device@localhost` chat may appear on the other device.

src/chat.rs

@@ -2298,6 +2298,10 @@ impl Chat {
     async fn get_sync_id(&self, context: &Context) -> Result<Option<SyncId>> {
         match self.typ {
             Chattype::Single => {
+                if self.is_device_talk() {
+                    return Ok(Some(SyncId::Device));
+                }
+
                 let mut r = None;
                 for contact_id in get_chat_contacts(context, self.id).await? {
                     if contact_id == ContactId::SELF && !self.is_self_talk() {
@@ -4750,6 +4754,9 @@ pub(crate) enum SyncId {
     Grpid(String),
     /// "Message-ID"-s, from oldest to latest. Used for ad-hoc groups.
     Msgids(Vec<String>),
+
+    // Special id for device chat.
+    Device,
 }
 
 /// An action synchronised to other devices.
@@ -4811,6 +4818,7 @@ impl Context {
                 ChatId::lookup_by_message(&msg)
                     .with_context(|| format!("No chat found for Message-IDs {msgids:?}"))?
             }
+            SyncId::Device => ChatId::get_for_contact(self, ContactId::DEVICE).await?,
         };
         match action {
             SyncAction::Block => chat_id.block_ex(self, Nosync).await,

src/chat/chat_tests.rs

@@ -3059,6 +3059,34 @@ async fn test_sync_visibility() -> Result<()> {
     Ok(())
 }
 
+/// Tests syncing of chat visibility on device message chat.
+///
+/// Previously due to a bug pinning "Device Messages"
+/// chat resulted in creation of `device@localhost` chat
+/// on another device.
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_sync_device_messages_visibility() -> Result<()> {
+    let mut tcm = TestContextManager::new();
+    let alice0 = &tcm.alice().await;
+    let alice1 = &tcm.alice().await;
+    for a in [alice0, alice1] {
+        a.set_config_bool(Config::SyncMsgs, true).await?;
+    }
+
+    let device_chat_id0 = ChatId::get_for_contact(alice0, ContactId::DEVICE).await?;
+    device_chat_id0
+        .set_visibility(alice0, ChatVisibility::Pinned)
+        .await?;
+
+    sync(alice0, alice1).await;
+
+    let device_chat_id1 = ChatId::get_for_contact(alice1, ContactId::DEVICE).await?;
+    let device_chat1 = Chat::load_from_db(alice1, device_chat_id1).await?;
+    assert_eq!(device_chat1.get_visibility(), ChatVisibility::Pinned);
+
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_sync_muted() -> Result<()> {
     let alice0 = &TestContext::new_alice().await;