fix: do not add QR inviter to groups immediately

By the time you scan the QR code,
inviter may not be in the group already.
In this case securejoin protocol will never complete.
If you then join the group in some other way,
this results in you implicitly adding that inviter
to the group.

Author: link2xt

src/receive_imf.rs

@@ -2841,6 +2841,16 @@ async fn apply_group_changes(
         if !is_from_in_chat {
             better_msg = Some(String::new());
         } else if let Some(key) = mime_parser.gossiped_keys.get(added_addr) {
+            if !chat_contacts.contains(&from_id) {
+                chat::add_to_chat_contacts_table(
+                    context,
+                    mime_parser.timestamp_sent,
+                    chat.id,
+                    &[from_id],
+                )
+                .await?;
+            }
+
             // TODO: if gossiped keys contain the same address multiple times,
             // we may lookup the wrong contact.
             // This can be fixed by looking at ChatGroupMemberAddedFpr,

src/securejoin/bob.rs

@@ -126,17 +126,6 @@ pub(super) async fn start_protocol(context: &Context, invite: QrInvite) -> Resul
     match invite {
         QrInvite::Group { .. } => {
             let joining_chat_id = joining_chat_id(context, &invite, private_chat_id).await?;
-            // We created the group already, now we need to add Alice to the group.
-            // The group will only become usable once the protocol is finished.
-            if !is_contact_in_chat(context, joining_chat_id, invite.contact_id()).await? {
-                chat::add_to_chat_contacts_table(
-                    context,
-                    time(),
-                    joining_chat_id,
-                    &[invite.contact_id()],
-                )
-                .await?;
-            }
             let msg = stock_str::secure_join_started(context, invite.contact_id()).await;
             chat::add_info_msg(context, joining_chat_id, &msg, time()).await?;
             Ok(joining_chat_id)