patch 8.0.0732: when updating a buffer modeless selection is lost commit https://github.com/vim/vim/commit/80dd3f9d41ce2ff6ab3544cdb266627bbdfc34a6 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Jul 19 12:51:52 2017 +0200 patch 8.0.0732: when updating a buffer modeless selection is lost Problem: When updating a buffer for a callback the modeless selection is lost. Solution: Do not insert or delete screen lines when redrawing for a callback and there is a modeless selection.

" Test for :cd

func Test_cd_large_path()
  " This used to crash with a heap write overflow.
  call assert_fails('cd ' . repeat('x', 5000), 'E472:')
endfunc

func Test_cd_up_and_down()
  let path = getcwd()
  cd ..
  exe 'cd ' . path
  call assert_equal(path, getcwd())
endfunc