patch 8.0.0388: filtering lines changes folds commit https://github.com/vim/vim/commit/1159b168dd94c1a25b4284c6544de385855df6f6 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Feb 28 21:53:56 2017 +0100 patch 8.0.0388: filtering lines changes folds Problem: filtering lines through "cat", without changing the line count, changes manual folds. Solution: Change how marks and folds are adjusted. (Matthew Malcomson, from neovim #6194.

" 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