Completing a task with subtasks is now reliable

Completing a parent task closes its subtasks too. On tasks with several subtasks that could previously fail partway through — the page would appear to do nothing, and the subtasks you expected to close would reappear the next time the view refreshed.

Closing a subtree is now a single operation, so it finishes quickly no matter how many subtasks are involved. In the rare case it can't finish, you'll get a clear message telling you the task was completed but its subtasks weren't, instead of a screen that looks like nothing happened.

One related change worth knowing: an automation rule that triggers on a status change now runs once, for the task you actually completed, rather than once for every subtask it closed alongside it.