Much like how MusicBrainz warns the user when they attempt to close the tab/window on the release editor - so should "add edition" and "add work" warn the user if they attempt to close such page; Provided some text has been written here
i.e, an opened, blank, add edition or add work tab/window should not do this.

Additionally it should not give a warning if a work or edition is "edited" but no change is made, once a change has been made, a warning on attempted close is apt.