fix: Keep email email contact in 1:1 chat if PGP contact has a different addr

If a contact did AEAP in the past, then it can happen that there are multiple contacts with the same email address but different keys.
In this case, we should make sure that we don't send messages to a different email address all of a sudden,
and that there aren't two 1:1 chats with the same contact.

Therefore, if the PGP contact has a different email address than the
email contact, we keep the email contact in 1:1 chats.

Author: Hocuri

src/sql/migrations.rs

@@ -1583,6 +1583,8 @@ fn migrate_pgp_contacts(
 
         let mut update_member_stmt = transaction
             .prepare("UPDATE chats_contacts SET contact_id=? WHERE contact_id=? AND chat_id=?")?;
+        let mut addr_cmp_stmt = transaction
+            .prepare("SELECT c.addr=d.addr FROM contacts c, contacts d WHERE c.id=? AND d.id=?")?;
         for chat in all_chats {
             let (chat_id, typ, grpid, protected) = chat.context("Step 24")?;
             // In groups, this also contains past members
@@ -1601,7 +1603,8 @@ fn migrate_pgp_contacts(
 
             let old_and_new_members = match typ {
                 // 1:1 chats retain:
-                // - email-contact if peerstate is in the "reset" state.
+                // - email-contact if peerstate is in the "reset" state,
+                //   or if there is no PGP-contact that has the right email address.
                 // - PGP-contact identified by the Autocrypt key if Autocrypt key does not match the verified key.
                 // - PGP-contact identified by the verified key if peerstate Autocrypt key matches the Verified key.
                 //   Since the autocrypt and verified PGP contact are identital in this case, we can add the AutocryptPgp contact,
@@ -1615,6 +1618,12 @@ fn migrate_pgp_contacts(
                         keep_email_contacts("No peerstate, or peerstate in 'reset' state");
                         continue;
                     };
+                    if !addr_cmp_stmt
+                        .query_row((old_member, new_contact), |row| row.get::<_, bool>(0))?
+                    {
+                        keep_email_contacts("PGP contact has different email");
+                        continue;
+                    }
                     vec![(*old_member, Some(new_contact))]
                 }