When entering a new post I inadvertently clicked the ‘Quit’ X box and correctly got the message asking me “Are you sure you want to quit? All unsaved changes will be lost.” I answered “No”, but the program quit anyway and my post was completely lost. This behaviour seems to be the same when editing a post.
I am using Version: 0.39.1 (build 15486)
Here is a short video of the problem.