commit https://github.com/vim/vim/commit/1610d052413e0ed664498853a47acc2d677a22d1 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 9 22:53:01 2016 +0200 patch 7.4.1913 Problem: When ":doautocmd" is used modelines are used even when no autocommands were executed. (Daniel Hahler) Solution: Skip processing modelines. (closes https://github.com/vim/vim/issues/854)

" Simplistic way to make spaces and Tabs visible

" This can be added to an already active syntax.

syn match Space " "
syn match Tab "\t"
if &background == "dark"
  hi def Space ctermbg=darkred guibg=#500000
  hi def Tab ctermbg=darkgreen guibg=#003000
else
  hi def Space ctermbg=lightred guibg=#ffd0d0
  hi def Tab ctermbg=lightgreen guibg=#d0ffd0
endif