patch 8.2.3476: renaming a buffer on startup may cause using freed memory Commit: https://github.com/vim/vim/commit/d3710cf01ef6ab1b2f233866ff01dab76686f642 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Oct 4 23:13:13 2021 +0100 patch 8.2.3476: renaming a buffer on startup may cause using freed memory Problem: Renaming a buffer on startup may cause using freed memory. Solution: Check if the buffer is used in a window. (closes https://github.com/vim/vim/issues/8955)

" 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