commit https://github.com/vim/vim/commit/d5d3d307ddb824f59a2f2516c4b6a6d48762aa58 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Mar 9 20:54:51 2016 +0100 patch 7.4.1526 Problem: Writing to file and not connecting a channel doesn't work for MS-Windows. Solution: Make it work. (Yasuhiro Matsumoto)

" Test for joining lines.

func Test_join_with_count()
  new
  call setline(1, ['one', 'two', 'three', 'four'])
  normal J
  call assert_equal('one two', getline(1))
  %del
  call setline(1, ['one', 'two', 'three', 'four'])
  normal 10J
  call assert_equal('one two three four', getline(1))
  quit!
endfunc