patch 8.1.0523: opening window from quickfix leaves empty buffer behind commit https://github.com/vim/vim/commit/b244373becbec124bee20dbbfd05365586cda8cd Author: Bram Moolenaar <Bram@vim.org> Date: Sun Nov 11 22:50:27 2018 +0100 patch 8.1.0523: opening window from quickfix leaves empty buffer behind Problem: Opening window from quickfix leaves empty buffer behind. Solution: Add qf_jump_newwin(). (Yegappan Lakshmanan, closes https://github.com/vim/vim/issues/2574)

" Test feedkeys() function.

func Test_feedkeys_x_with_empty_string()
  new
  call feedkeys("ifoo\<Esc>")
  call assert_equal('', getline('.'))
  call feedkeys('', 'x')
  call assert_equal('foo', getline('.'))

  " check it goes back to normal mode immediately.
  call feedkeys('i', 'x')
  call assert_equal('foo', getline('.'))
  quit!
endfunc