Undo commands, without a query or an error
See undo for an introduction to undoing commands.
The keyword command :ubu! is the same as :ubu, but
with a guarantee that it is ``error-free.'' More precisely, the error-triple returned by :ubu! will always be of the form (mv nil
val state). :Oops will undo the last :ubu!. Also see
ubu, ubu?, ubt, ubt!, ubt?, and u.