patch 8.1.1665: crash when popup window with mask is below the screen commit https://github.com/vim/vim/commit/b4207474780569bcc9840e03f13edb5d9c2554f5 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Jul 12 16:05:45 2019 +0200 patch 8.1.1665: crash when popup window with mask is below the screen Problem: Crash when popup window with mask is below the screen. Solution: Correct boundary check.

" 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