I'm using 13.1.4 and think I'mseeing new behaviour thats confusing me a little. When I edit a table (this ones MySQL5) and double-click an empty boolean field checkbox. It now changes from  to [-] then if I doubleclick it again it changes from [-] to [v] (tick). Pretty sure it used to have just two states  and [v] what is this intermidate [-] state? how do booleans have three states?