commit https://github.com/vim/vim/commit/8f79acdf7ede2693fbda53c3c9693f16db4f193b Author: Bram Moolenaar <Bram@vim.org> Date: Fri Jan 1 14:48:20 2016 +0100 patch 7.4.1017 Problem: When there is a backslash in an option ":set -=" doesn't work. Solution: Handle a backslash better. (Jacob Niehus) Add a new test, merge in old test.

" Vim indent file
" Language:	Lisp
" Maintainer:    Sergey Khorev <sergey.khorev@gmail.com>
" URL:		 http://sites.google.com/site/khorser/opensource/vim
" Last Change:	2012 Jan 10

" Only load this indent file when no other was loaded.
if exists("b:did_indent")
   finish
endif
let b:did_indent = 1

setlocal ai nosi

let b:undo_indent = "setl ai< si<"