feat: Disable sending sync messages for bots (#5705)

If currently there are no multi-device bots, let's disable sync messages for bots at all. Another
option is to auto-disable sync messages when `Config::Bot` is set, so sync messages can be reenabled
if needed. But let's leave this option for the future.

src/config.rs

@@ -314,7 +314,8 @@ pub enum Config {
     #[strum(props(default = "0"))]
     DownloadLimit,
 
-    /// Enable sending and executing (applying) sync messages. Sending requires `BccSelf` to be set.
+    /// Enable sending and executing (applying) sync messages. Sending requires `BccSelf` to be set
+    /// and `Bot` unset.
     #[strum(props(default = "1"))]
     SyncMsgs,
 
@@ -494,11 +495,10 @@ impl Context {
     }
 
     /// Returns true if sync messages should be sent.
-    ///
-    /// This requires that both `SyncMsgs` and `BccSelf` settings are enabled.
     pub(crate) async fn should_send_sync_msgs(&self) -> Result<bool> {
         Ok(self.get_config_bool(Config::SyncMsgs).await?
-            && self.get_config_bool(Config::BccSelf).await?)
+            && self.get_config_bool(Config::BccSelf).await?
+            && !self.get_config_bool(Config::Bot).await?)
     }
 
     /// Gets configured "delete_server_after" value.

src/sync.rs

@@ -322,7 +322,7 @@ mod tests {
     use super::*;
     use crate::chatlist::Chatlist;
     use crate::contact::{Contact, Origin};
-    use crate::test_utils::TestContext;
+    use crate::test_utils::{TestContext, TestContextManager};
     use crate::tools::SystemTime;
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
@@ -595,4 +595,30 @@ mod tests {
 
         Ok(())
     }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_bot_no_sync_msgs() -> Result<()> {
+        let mut tcm = TestContextManager::new();
+        let alice = &tcm.alice().await;
+        let bob = &tcm.bob().await;
+        alice.set_config_bool(Config::SyncMsgs, true).await?;
+        let chat_id = alice.create_chat(bob).await.id;
+
+        chat::send_text_msg(alice, chat_id, "hi".to_string()).await?;
+        alice
+            .set_config(Config::Displayname, Some("Alice Human"))
+            .await?;
+        alice.pop_sent_msg().await; // Sync message
+        let msg = bob.recv_msg(&alice.pop_sent_msg().await).await;
+        assert_eq!(msg.text, "hi");
+
+        alice.set_config_bool(Config::Bot, true).await?;
+        chat::send_text_msg(alice, chat_id, "hi".to_string()).await?;
+        alice
+            .set_config(Config::Displayname, Some("Alice Bot"))
+            .await?;
+        let msg = bob.recv_msg(&alice.pop_sent_msg().await).await;
+        assert_eq!(msg.text, "hi");
+        Ok(())
+    }
 }