fix: Make pre-messages w/o text want MDNs (#8004)

Maybe it's even good that MDNs will be sent for pre-messages only having placeholder text with the
viewtype and size, at least this way we notify the contact that we've noticed the message. Anyway,
with adding message previews the problem will be solved for the corresponding viewtypes.

src/tests/pre_messages/receiving.rs

@@ -261,6 +261,61 @@ async fn test_lost_pre_msg() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_pre_msg_mdn_before_sending_full() -> Result<()> {
+    pre_msg_mdn_before_sending_full("").await
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_pre_msg_mdn_before_sending_full_with_text() -> Result<()> {
+    pre_msg_mdn_before_sending_full("text").await
+}
+
+async fn pre_msg_mdn_before_sending_full(text: &str) -> Result<()> {
+    let mut tcm = TestContextManager::new();
+    let alice = &tcm.alice().await;
+    let bob = &tcm.bob().await;
+    let alice_chat_id = alice.create_group_with_members("", &[bob]).await;
+
+    let file_bytes = include_bytes!("../../../test-data/image/screenshot.gif");
+    let mut msg = Message::new(Viewtype::Image);
+    msg.set_file_from_bytes(alice, "a.jpg", file_bytes, None)?;
+    msg.set_text(text.to_string());
+    chat::send_msg(alice, alice_chat_id, &mut msg).await?;
+    let rev_order = false;
+    let pre_msg = alice.pop_sent_msg_ex(rev_order).await.unwrap();
+    let alice_msg_id = msg.id;
+
+    let msg = bob.recv_msg(&pre_msg).await;
+    assert_eq!(msg.download_state, DownloadState::Available);
+    assert_eq!(msg.id.get_state(bob).await?, MessageState::InFresh);
+    assert_eq!(msg.text, text);
+    assert!(msg.param.get_bool(Param::WantsMdn).unwrap_or_default());
+    msg.chat_id.accept(bob).await?;
+    markseen_msgs(bob, vec![msg.id]).await?;
+    assert_eq!(msg.id.get_state(bob).await?, MessageState::InSeen);
+    assert_eq!(
+        bob.sql
+            .count(
+                "SELECT COUNT(*) FROM smtp_mdns WHERE from_id=?",
+                (msg.from_id,)
+            )
+            .await?,
+        1
+    );
+    assert_eq!(
+        alice_msg_id.get_state(alice).await?,
+        MessageState::OutPending
+    );
+
+    let _full_msg = alice.pop_sent_msg().await;
+    assert_eq!(
+        alice_msg_id.get_state(alice).await?,
+        MessageState::OutDelivered
+    );
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn test_post_msg_bad_sender() -> Result<()> {
     let mut tcm = TestContextManager::new();
@@ -743,7 +798,10 @@ async fn test_markseen_pre_msg() -> Result<()> {
     assert_eq!(
         alice
             .sql
-            .count("SELECT COUNT(*) FROM smtp_mdns", ())
+            .count(
+                "SELECT COUNT(*) FROM smtp_mdns WHERE from_id=?",
+                (msg.from_id,)
+            )
             .await?,
         1
     );