patch 8.0.0537: illegal memory access with :z and large count commit https://github.com/vim/vim/commit/fa0ad0bb0b4255e64ebcf9269d60a942e0ae7ff9 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Apr 2 15:45:17 2017 +0200 patch 8.0.0537: illegal memory access with :z and large count Problem: Illegal memory access with :z and large count. Solution: Check for number overflow, using long instead of int. (Dominique Pelle, closes #1612)

" 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