Rewrite member added/removed messages even if the change is not allowed

PR https://github.com/deltachat/deltachat-core-rust/pull/4529

src/chat.rs

@@ -4083,6 +4083,67 @@ mod tests {
         Ok(())
     }
 
+    /// Test simultaneous removal of user from the chat and leaving the group.
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_simultaneous_member_remove() -> Result<()> {
+        let mut tcm = TestContextManager::new();
+
+        let alice = tcm.alice().await;
+        let bob = tcm.bob().await;
+
+        alice.set_config(Config::E2eeEnabled, Some("0")).await?;
+        bob.set_config(Config::E2eeEnabled, Some("0")).await?;
+
+        let alice_bob_contact_id = Contact::create(&alice, "Bob", "bob@example.net").await?;
+        let alice_fiona_contact_id = Contact::create(&alice, "Fiona", "fiona@example.net").await?;
+        let alice_claire_contact_id =
+            Contact::create(&alice, "Claire", "claire@example.net").await?;
+
+        // Create and promote a group.
+        let alice_chat_id =
+            create_group_chat(&alice, ProtectionStatus::Unprotected, "Group chat").await?;
+        add_contact_to_chat(&alice, alice_chat_id, alice_bob_contact_id).await?;
+        add_contact_to_chat(&alice, alice_chat_id, alice_fiona_contact_id).await?;
+        let alice_sent_msg = alice
+            .send_text(alice_chat_id, "Hi! I created a group.")
+            .await;
+        let bob_received_msg = bob.recv_msg(&alice_sent_msg).await;
+
+        let bob_chat_id = bob_received_msg.get_chat_id();
+        bob_chat_id.accept(&bob).await?;
+
+        // Alice adds Claire to the chat.
+        add_contact_to_chat(&alice, alice_chat_id, alice_claire_contact_id).await?;
+        let alice_sent_add_msg = alice.pop_sent_msg().await;
+
+        // Alice removes Bob from the chat.
+        remove_contact_from_chat(&alice, alice_chat_id, alice_bob_contact_id).await?;
+        let alice_sent_remove_msg = alice.pop_sent_msg().await;
+
+        // Bob leaves the chat.
+        remove_contact_from_chat(&bob, bob_chat_id, ContactId::SELF).await?;
+
+        // Bob receives a msg about Alice adding Claire to the group.
+        let bob_received_add_msg = bob.recv_msg(&alice_sent_add_msg).await;
+
+        // Test that add message is rewritten.
+        assert_eq!(
+            bob_received_add_msg.get_text(),
+            "Member claire@example.net added by alice@example.org."
+        );
+
+        // Bob receives a msg about Alice removing him from the group.
+        let bob_received_remove_msg = bob.recv_msg(&alice_sent_remove_msg).await;
+
+        // Test that remove message is rewritten.
+        assert_eq!(
+            bob_received_remove_msg.get_text(),
+            "Member Me (bob@example.net) removed by alice@example.org."
+        );
+
+        Ok(())
+    }
+
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_modify_chat_multi_device() -> Result<()> {
         let a1 = TestContext::new_alice().await;

src/receive_imf.rs

@@ -1682,6 +1682,13 @@ async fn apply_group_changes(
 
     if let Some(removed_addr) = mime_parser.get_header(HeaderDef::ChatGroupMemberRemoved) {
         removed_id = Contact::lookup_id_by_addr(context, removed_addr, Origin::Unknown).await?;
+
+        better_msg = if removed_id == Some(from_id) {
+            Some(stock_str::msg_group_left_local(context, from_id).await)
+        } else {
+            Some(stock_str::msg_del_member_local(context, removed_addr, from_id).await)
+        };
+
         if let Some(contact_id) = removed_id {
             if allow_member_list_changes {
                 // Remove a single member from the chat.
@@ -1689,12 +1696,6 @@ async fn apply_group_changes(
                     chat::remove_from_chat_contacts_table(context, chat_id, contact_id).await?;
                     send_event_chat_modified = true;
                 }
-
-                better_msg = if contact_id == from_id {
-                    Some(stock_str::msg_group_left_local(context, from_id).await)
-                } else {
-                    Some(stock_str::msg_del_member_local(context, removed_addr, from_id).await)
-                };
             } else {
                 info!(
                     context,
@@ -1705,6 +1706,8 @@ async fn apply_group_changes(
             warn!(context, "Removed {removed_addr:?} has no contact id.")
         }
     } else if let Some(added_addr) = mime_parser.get_header(HeaderDef::ChatGroupMemberAdded) {
+        better_msg = Some(stock_str::msg_add_member_local(context, added_addr, from_id).await);
+
         if allow_member_list_changes {
             // Add a single member to the chat.
             if !recreate_member_list {
@@ -1717,8 +1720,6 @@ async fn apply_group_changes(
                     warn!(context, "Added {added_addr:?} has no contact id.")
                 }
             }
-
-            better_msg = Some(stock_str::msg_add_member_local(context, added_addr, from_id).await);
         } else {
             info!(context, "Ignoring addition of {added_addr:?} to {chat_id}.");
         }