commit https://github.com/vim/vim/commit/1d478a6242871dcf4566814d3c6208df17991426 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Sep 29 14:01:12 2015 +0200 patch 7.4.886 Problem: Windows7: Switching screen buffer causes flicker when using system(). Solution: Instead of actually switching screen buffer, duplicate the handle. (Yasuhiro Matsumoto)

" 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