fix: Fail receive_imf to not tombstone reaction if the referenced message isn't found

A reaction may arrive earler than the referenced message in case of multi-transport. By not creating
a tombstone we still can receive it later on another transport.

deltachat-rpc-client/tests/test_something.py

@@ -348,7 +348,7 @@ def test_receive_imf_failure(acfactory) -> None:
         snapshot.text == "❌ Failed to receive a message:"
         " Condition failed: `!context.get_config_bool(Config::SimulateReceiveImfError).await?`."
         f" Core version {version}."
-        " Please report this bug to delta@merlinux.eu or https://support.delta.chat/."
+        " Please report this bug to delta@merlinux.eu or https://support.delta.chat/"
     )
 
     # The failed message doesn't break the IMAP loop.

src/imap.rs

@@ -1383,13 +1383,15 @@ impl Session {
                 let res = receive_imf_inner(context, rfc724_mid, body, is_seen).await;
                 let received_msg = match res {
                     Err(err) => {
-                        warn!(context, "receive_imf error: {err:#}.");
-
-                        let text = format!(
-                            "❌ Failed to receive a message: {err:#}. Core version v{DC_VERSION_STR}. Please report this bug to delta@merlinux.eu or https://support.delta.chat/.",
-                        );
-                        let mut msg = Message::new_text(text);
-                        add_device_msg(context, None, Some(&mut msg)).await?;
+                        let err = format!("{err:#}");
+                        warn!(context, "receive_imf error: {err}.");
+                        if !err.contains("(SKIP_DEVICE_MSG)") {
+                            let text = format!(
+                                "❌ Failed to receive a message: {err}. Core version v{DC_VERSION_STR}. Please report this bug to delta@merlinux.eu or https://support.delta.chat/",
+                            );
+                            let mut msg = Message::new_text(text);
+                            add_device_msg(context, None, Some(&mut msg)).await?;
+                        }
                         None
                     }
                     Ok(msg) => msg,

src/reaction.rs

@@ -18,7 +18,7 @@ use std::cmp::Ordering;
 use std::collections::BTreeMap;
 use std::fmt;
 
-use anyhow::Result;
+use anyhow::{Result, bail};
 use serde::{Deserialize, Serialize};
 
 use crate::chat::{Chat, ChatId, send_msg};
@@ -259,9 +259,8 @@ pub(crate) async fn set_msg_reaction(
             });
         }
     } else {
-        info!(
-            context,
-            "Can't assign reaction to unknown message with Message-ID {}", in_reply_to
+        bail!(
+            "Can't assign reaction to unknown message with Message-ID {in_reply_to} (SKIP_DEVICE_MSG)"
         );
     }
     Ok(())
@@ -519,6 +518,54 @@ Content-Disposition: reaction\n\
         Ok(())
     }
 
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_reaction_and_multitransport() -> Result<()> {
+        let mut tcm = TestContextManager::new();
+        let alice = &tcm.alice().await;
+        let device_chat_id = ChatId::get_for_contact(alice, ContactId::DEVICE).await?;
+        let n_device_msgs = get_chat_msgs(alice, device_chat_id).await?.len();
+
+        let reaction_bytes = "To: alice@example.org, claire@example.org\n\
+From: bob@example.net\n\
+Date: Today, 29 February 2021 00:00:10 -800\n\
+Message-ID: 56789@example.net\n\
+In-Reply-To: 12345@example.org\n\
+Content-Type: text/plain; charset=utf-8\n\
+Content-Disposition: reaction\n\
+\n\
+\u{1F44D}"
+            .as_bytes();
+        // Alice receives a reaction to Claire's message from Bob earler than the message itself
+        // because Bob knows about Alice's new transport.
+        assert!(receive_imf(alice, reaction_bytes, false).await.is_err());
+
+        let msg_id = receive_imf(
+            alice,
+            "To: alice@example.org, bob@example.net\n\
+From: claire@example.org\n\
+Date: Today, 29 February 2021 00:00:00 -800\n\
+Message-ID: 12345@example.org\n\
+\n\
+Can we chat at 1pm pacific, today?"
+                .as_bytes(),
+            false,
+        )
+        .await?
+        .unwrap()
+        .msg_ids[0];
+
+        // Finally the reaction arrives on Alice's older transport.
+        receive_imf(alice, reaction_bytes, false).await?;
+        let reactions = get_msg_reactions(alice, msg_id).await?;
+        assert_eq!(reactions.to_string(), "👍1");
+
+        assert_eq!(
+            get_chat_msgs(alice, device_chat_id).await?.len(),
+            n_device_msgs
+        );
+        Ok(())
+    }
+
     async fn expect_reactions_changed_event(
         t: &TestContext,
         expected_chat_id: ChatId,