commit https://github.com/vim/vim/commit/864293abb72d62604d8d6b458addfb43c14230c3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 2 13:40:04 2016 +0200 patch 7.4.1871 Problem: Appending to the quickfix list while the quickfix window is open is very slow. Solution: Do not delete all the lines, only append the new ones. Avoid using a window while updating the list. (closes #841)

" Vim filetype plugin
" Language:		JSON
" Maintainer:		David Barnett <daviebdawg+vim@gmail.com>
" Last Change:		2014 Jul 16

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

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

setlocal formatoptions-=t

" JSON has no comments.
setlocal comments=
setlocal commentstring=