patch 8.1.1653: ubsan warns for possibly passing NULL pointer commit https://github.com/vim/vim/commit/0d07155c8bbaca1a527b79da358438253a60839f Author: Bram Moolenaar <Bram@vim.org> Date: Mon Jul 8 22:04:03 2019 +0200 patch 8.1.1653: ubsan warns for possibly passing NULL pointer Problem: Ubsan warns for possibly passing NULL pointer. Solution: Skip code when length is zero. (Dominique Pelle, closes https://github.com/vim/vim/issues/4631)

" Vim filetype plugin
" Language:	Dockerfile
" Maintainer:   Honza Pokorny <http://honza.ca>
" Last Change:	2014 Aug 29

" Only do this when not done yet for this buffer
if exists("b:did_ftplugin")
  finish
endif

" Don't load another plugin for this buffer
let b:did_ftplugin = 1

let b:undo_ftplugin = "setl commentstring<"

setlocal commentstring=#\ %s