feat: do not replace messages with an error on verification failure

Author: link2xt

src/mimeparser.rs

@@ -1593,15 +1593,6 @@ impl MimeMessage {
         }
     }
 
-    pub fn replace_msg_by_error(&mut self, error_msg: &str) {
-        self.is_system_message = SystemMessage::Unknown;
-        if let Some(part) = self.parts.first_mut() {
-            part.typ = Viewtype::Text;
-            part.msg = format!("[{error_msg}]");
-            self.parts.truncate(1);
-        }
-    }
-
     pub(crate) fn get_rfc724_mid(&self) -> Option<String> {
         self.get_header(HeaderDef::MessageId)
             .and_then(|msgid| parse_message_id(msgid).ok())

src/receive_imf.rs

@@ -1864,25 +1864,6 @@ async fn add_parts(
         None
     };
 
-    let mut verification_failed = false;
-    if !chat_id.is_special() && is_partial_download.is_none() {
-        // For outgoing emails in the 1:1 chat we have an exception that
-        // they are allowed to be unencrypted:
-        // 1. They can't be an attack (they are outgoing, not incoming)
-        // 2. Probably the unencryptedness is just a temporary state, after all
-        //    the user obviously still uses DC
-        //    -> Showing info messages every time would be a lot of noise
-        // 3. The info messages that are shown to the user ("Your chat partner
-        //    likely reinstalled DC" or similar) would be wrong.
-        if chat.is_protected() && (mime_parser.incoming || chat.typ != Chattype::Single) {
-            if let VerifiedEncryption::NotVerified(err) = verified_encryption {
-                verification_failed = true;
-                warn!(context, "Verification problem: {err:#}.");
-                let s = format!("{err}. Re-download the message or see 'Info' for more details");
-                mime_parser.replace_msg_by_error(&s);
-            }
-        }
-    }
     drop(chat); // Avoid using stale `chat` object.
 
     let sort_timestamp = tweak_sort_timestamp(
@@ -2156,10 +2137,6 @@ RETURNING id
                         DownloadState::Available
                     } else if mime_parser.decrypting_failed {
                         DownloadState::Undecipherable
-                    } else if verification_failed {
-                        // Verification can fail because of message reordering. Re-downloading the
-                        // message should help if so.
-                        DownloadState::Available
                     } else {
                         DownloadState::Done
                     },

src/receive_imf/receive_imf_tests.rs

@@ -5133,23 +5133,9 @@ async fn test_unverified_member_msg() -> Result<()> {
     let fiona_chat_id = fiona.get_last_msg().await.chat_id;
     let fiona_sent_msg = fiona.send_text(fiona_chat_id, "Hi").await;
 
-    // The message can't be verified, but the user can re-download it.
-    let bob_msg = bob.recv_msg(&fiona_sent_msg).await;
-    assert_eq!(bob_msg.download_state, DownloadState::Available);
-    assert!(
-        bob_msg
-            .text
-            .contains("Re-download the message or see 'Info' for more details")
-    );
-
-    // Shift the time by 1 week to trigger gossiping.
-    SystemTime::shift(Duration::from_secs(3600 * 24 * 7));
-    let alice_sent_msg = alice
-        .send_text(alice_chat_id, "Hi all, it's Alice introducing Fiona")
-        .await;
-    bob.recv_msg(&alice_sent_msg).await;
-
-    // Now Bob has Fiona's key and can verify the message.
+    // The message is by non-verified member,
+    // but the checks have been removed
+    // and the message should be downloaded as usual.
     let bob_msg = bob.recv_msg(&fiona_sent_msg).await;
     assert_eq!(bob_msg.download_state, DownloadState::Done);
     assert_eq!(bob_msg.text, "Hi");