patch 9.0.1036: undo misbehaves when writing from an insert mode mapping Commit: https://github.com/vim/vim/commit/3f8f82772313af9f2417b06651f30988b63e1c96 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Dec 8 21:49:35 2022 +0000 patch 9.0.1036: undo misbehaves when writing from an insert mode mapping Problem: Undo misbehaves when writing from an insert mode mapping. Solution: Sync undo when writing. (closes https://github.com/vim/vim/issues/11674)

" Vim filetype plugin
" Language:	roff(7)
" Maintainer:	Aman Verma
" Homepage:	https://github.com/a-vrma/vim-nroff-ftplugin
" Previous Maintainer:	Chris Spiegel <cspiegel@gmail.com>
" Last Change:	2020 Nov 21

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

setlocal commentstring=.\\\"%s
setlocal comments=:.\\\"
setlocal sections+=Sh

let b:undo_ftplugin = 'setlocal commentstring< comments< sections<'