commit https://github.com/vim/vim/commit/680e015bfe19be6772d3bd754486fbd45c1a9d3b Author: Bram Moolenaar <Bram@vim.org> Date: Sun Sep 25 20:54:11 2016 +0200 patch 8.0.0010 Problem: Crash when editing file that starts with crypt yeader. (igor2x) Solution: Check for length of text. (Christian Brabandt) Add a test.

" 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