gistfile1.vim

function! s:set_cursor() abort
  let s:oldline = exists('s:newline') ? s:newline : 5
  let s:newline = line('.')
  let headoff = s:headoff + 2 + s:secoff

  " going BOTH WAYS !!!!
  let direction = 2 * (s:newline > s:oldline) - 1 
  while index(s:section_header_lines, s:newline) != -1
    let s:newline += direction
  endwhile
  if empty(getline(s:newline)) | let s:newline += direction | endif
  if index([0, s:lastline, headoff], s:newline) == -1 | let s:newline = [0, s:lastline, headoff][direction] | endif 

  call cursor(s:newline, 5)
endfunction