Do not reset user status after receiving a read receipt

Read receipts never contain the signature, so previously receiving it
cleared the status.

python/tests/test_account.py

@@ -2187,9 +2187,25 @@ class TestOnlineAccount:
         chat12 = acfactory.get_accepted_chat(ac1, ac2)
         ac1.set_config("selfstatus", "New status")
         chat12.send_text("hi")
-        msg = ac2._evtracker.wait_next_incoming_message()
+        msg_received = ac2._evtracker.wait_next_incoming_message()
-        assert msg.text == "hi"
+        assert msg_received.text == "hi"
-        assert msg.get_sender_contact().status == "New status"
+        assert msg_received.get_sender_contact().status == "New status"
+
+        # Send a reply from ac2 to ac1 so ac1 can send a read receipt.
+        reply_msg = msg_received.chat.send_text("reply")
+        reply_msg_received = ac1._evtracker.wait_next_incoming_message()
+        assert reply_msg_received.text == "reply"
+
+        # Send read receipt from ac1 to ac2.
+        # It does not contain the signature.
+        ac1.mark_seen_messages([reply_msg_received])
+        ev = ac2._evtracker.get_matching("DC_EVENT_MSG_READ")
+        assert ev.data1 == reply_msg.chat.id
+        assert ev.data2 == reply_msg.id
+        assert reply_msg.is_out_mdn_received()
+
+        # Test that the status is not cleared as a result of receiving a read receipt.
+        assert msg_received.get_sender_contact().status == "New status"
 
         ac1.set_config("selfstatus", "")
         chat12.send_text("hello")

src/dc_receive_imf.rs

@@ -237,14 +237,18 @@ pub(crate) async fn dc_receive_imf_inner(
     }
 
     // Always update the status, even if there is no footer, to allow removing the status.
-    if let Err(err) = contact::set_status(
+    //
-        context,
+    // Ignore MDNs though, as they never contain the signature even if user has set it.
-        from_id,
+    if mime_parser.mdn_reports.is_empty() {
-        mime_parser.footer.clone().unwrap_or_default(),
+        if let Err(err) = contact::set_status(
-    )
+            context,
-    .await
+            from_id,
-    {
+            mime_parser.footer.clone().unwrap_or_default(),
-        warn!(context, "cannot update contact status: {}", err);
+        )
+        .await
+        {
+            warn!(context, "cannot update contact status: {}", err);
+        }
     }
 
     // Get user-configured server deletion