patch 8.2.4219: reading before the start of the line Commit: https://github.com/vim/vim/commit/44db8213d38c39877d2148eff6a72f4beccfb94e Author: Bram Moolenaar <Bram@vim.org> Date: Tue Jan 25 21:26:17 2022 +0000 patch 8.2.4219: reading before the start of the line Problem: Reading before the start of the line. Solution: Check boundary before trying to read the character.

" Vim indent file
" Language:	Mail
" Maintainer:	Bram Moolenaar
" Last Change:	2021 Sep 26

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=

let b:undo_indent = "setl ai< cin< inde< si<"