commit https://github.com/vim/vim/commit/6835dc61aebca2b602d85a9d63c449ace58683b4 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jul 24 17:33:05 2016 +0200 patch 7.4.2100 Problem: "cgn" and "dgn" do not work correctly with a single character match and the replacement includes the searched pattern. (John Beckett) Solution: If the match is found in the wrong column try in the next column. Turn the test into new style. (Christian Brabandt)

" Test matchstrpos

func Test_matchstrpos()
  call assert_equal(['ing', 4, 7], matchstrpos('testing', 'ing'))

  call assert_equal(['ing', 4, 7], matchstrpos('testing', 'ing', 2))

  call assert_equal(['', -1, -1], matchstrpos('testing', 'ing', 5))

  call assert_equal(['ing', 1, 4, 7], matchstrpos(['vim', 'testing', 'execute'], 'ing'))

  call assert_equal(['', -1, -1, -1], matchstrpos(['vim', 'testing', 'execute'], 'img'))
endfunc