patch 8.0.1632: in a terminal dump NUL and space are different commit https://github.com/vim/vim/commit/47015b80a0b0ff74ba7cb597d5959604b6e9a511 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Mar 23 22:10:34 2018 +0100 patch 8.0.1632: in a terminal dump NUL and space are different Problem: In a terminal dump NUL and space considered are different, although they are displayed the same. Solution: When encountering NUL handle it like space.

" Vim indent file
" Language:	Mail
" Maintainer:	Bram Moolenaar
" Last Change:	2009 Jun 03

if exists("b:did_indent")
  finish
endif
let b:did_indent = 1

" What works best is auto-indenting, disable other indenting.
" For formatting see the ftplugin.
setlocal autoindent nosmartindent nocindent indentexpr=