fix: Emit WebxdcInstanceDeleted events when deleting a chat (#6670)

Author: iequidoo

Diff for: src/chat.rs

@@ -793,6 +793,13 @@ impl ChatId {
         context
             .sql
             .transaction(|transaction| {
+                let mut stmt = transaction.prepare("SELECT id FROM msgs WHERE chat_id=? AND type=?")?;
+                let rows = stmt.query_map((self, Viewtype::Webxdc), |row| row.get(0))?;
+                // Let's emit events optimistically and not return webxdc `MsgId`s from the
+                // transaction to not add LIMIT to SELECT above.
+                for id in rows {
+                    context.emit_event(EventType::WebxdcInstanceDeleted { msg_id: id? });
+                }
                 transaction.execute(
                     "UPDATE imap SET target=? WHERE rfc724_mid IN (SELECT rfc724_mid FROM msgs WHERE chat_id=?)",
                     (delete_msgs_target, self,),

Diff for: src/webxdc/webxdc_tests.rs

@@ -1789,6 +1789,23 @@ async fn test_webxdc_delete_event() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_chat_delete() -> Result<()> {
+    let alice = &TestContext::new_alice().await;
+    let chat_id = create_group_chat(alice, ProtectionStatus::Unprotected, "foo").await?;
+    let instance = send_webxdc_instance(alice, chat_id).await?;
+    chat_id.delete(alice).await?;
+    let EventType::WebxdcInstanceDeleted { msg_id } = alice
+        .evtracker
+        .get_matching(|evt| matches!(evt, EventType::WebxdcInstanceDeleted { .. }))
+        .await
+    else {
+        unreachable!();
+    };
+    assert_eq!(msg_id, instance.id);
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn change_logging_webxdc() -> Result<()> {
     let alice = TestContext::new_alice().await;