commit https://github.com/vim/vim/commit/a742e084b677f76c67e9e52c4f9fb9ab24002e20 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Apr 5 21:10:38 2016 +0200 patch 7.4.1711 Problem: When using try/catch in 'statusline' it is still considered an error and the status line will be disabled. Solution: Check did_emsg instead of called_emsg. (haya14busa, closes https://github.com/vim/vim/issues/729)

" 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