commit https://github.com/vim/vim/commit/d29459baa61819e59961804ed258efac5733ec70 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Aug 26 22:29:11 2016 +0200 patch 7.4.2263 Problem: :filter does not work for many commands. Can only get matching messages. Solution: Make :filter work for :command, :map, :list, :number and :print. Make ":filter!" show non-matching lines.

" Tests for :undo

func Test_ex_undo()
  new ex-undo
  setlocal ul=10
  exe "normal ione\n\<Esc>"
  setlocal ul=10
  exe "normal itwo\n\<Esc>"
  setlocal ul=10
  exe "normal ithree\n\<Esc>"
  call assert_equal(4, line('$'))
  undo
  call assert_equal(3, line('$'))
  undo 1
  call assert_equal(2, line('$'))
  undo 0
  call assert_equal(1, line('$'))
  quit!
endfunc