patch 8.2.1821: Vim9: concatenating to a NULL list doesn't work Commit: https://github.com/vim/vim/commit/1a73923705744ab8297dd856d194e20297563456 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Oct 10 15:37:58 2020 +0200 patch 8.2.1821: Vim9: concatenating to a NULL list doesn't work Problem: Vim9: concatenating to a NULL list doesn't work. Solution: Handle a NULL list like an empty list. (closes https://github.com/vim/vim/issues/7064)

" Vim filetype plugin file
" Language:		Configuration File
" Maintainer:		Christian Brabandt <cb@256bit.org>
" Latest Revision:	2018-12-24

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

let s:cpo_save = &cpo
set cpo&vim

let b:undo_ftplugin = "setl cms< fo<"

setlocal commentstring=#\ %s formatoptions-=t formatoptions+=croql

let &cpo = s:cpo_save
unlet s:cpo_save