fix: do not apply group changes to special chats

This is a similar check to the one we have in `save_locations`.

src/receive_imf.rs

@@ -1723,6 +1723,10 @@ async fn apply_group_changes(
     to_ids: &[ContactId],
     is_partial_download: bool,
 ) -> Result<Vec<String>> {
+    if chat_id.is_special() {
+        // Do not apply group changes to the trash chat.
+        return Ok(Vec::new());
+    }
     let mut chat = Chat::load_from_db(context, chat_id).await?;
     if chat.typ != Chattype::Group {
         return Ok(Vec::new());

src/receive_imf/tests.rs

@@ -3686,6 +3686,34 @@ async fn test_mua_can_readd() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_member_left_does_not_create_chat() -> Result<()> {
+    let alice = TestContext::new_alice().await;
+    let bob = TestContext::new_bob().await;
+    let alice_chat_id = create_group_chat(&alice, ProtectionStatus::Unprotected, "Group").await?;
+    add_contact_to_chat(
+        &alice,
+        alice_chat_id,
+        Contact::create(&alice, "bob", &bob.get_config(Config::Addr).await?.unwrap()).await?,
+    )
+    .await?;
+    send_text_msg(&alice, alice_chat_id, "populate".to_string()).await?;
+    alice.pop_sent_msg().await;
+
+    // Bob only received a message of Alice leaving the group.
+    // This should not create the group.
+    //
+    // The reason is to avoid recreating deleted chats,
+    // especially the chats that were created due to "split group" bugs
+    // which some members simply deleted and some members left,
+    // recreating the chat for others.
+    remove_contact_from_chat(&alice, alice_chat_id, ContactId::SELF).await?;
+    let bob_chat_id = bob.recv_msg(&alice.pop_sent_msg().await).await.chat_id;
+    assert!(bob_chat_id.is_trash());
+
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_recreate_member_list_on_missing_add_of_self() -> Result<()> {
     let alice = TestContext::new_alice().await;
@@ -3699,11 +3727,14 @@ async fn test_recreate_member_list_on_missing_add_of_self() -> Result<()> {
     .await?;
     send_text_msg(&alice, alice_chat_id, "populate".to_string()).await?;
     alice.pop_sent_msg().await;
-    remove_contact_from_chat(&alice, alice_chat_id, ContactId::SELF).await?;
+
+    send_text_msg(&alice, alice_chat_id, "second message".to_string()).await?;
+
     let bob_chat_id = bob.recv_msg(&alice.pop_sent_msg().await).await.chat_id;
+    assert!(!bob_chat_id.is_special());
 
     // Bob missed the message adding them, but must recreate the member list.
-    assert_eq!(get_chat_contacts(&bob, bob_chat_id).await?.len(), 1);
+    assert_eq!(get_chat_contacts(&bob, bob_chat_id).await?.len(), 2);
     assert!(is_contact_in_chat(&bob, bob_chat_id, ContactId::SELF).await?);
     Ok(())
 }