commit https://github.com/vim/vim/commit/18dfb4404a618c52ee7138630a2381aed4d66eaf Author: Bram Moolenaar <Bram@vim.org> Date: Tue May 31 22:31:23 2016 +0200 patch 7.4.1862 Problem: string() with repeated argument does not give a result usable by eval(). Solution: Refactor echo_striong and tv2string(), moving the common part to echo_string_core(). (Ken Takata)

" Settings for test script execution
" Always use "COMMAND.COM", don't use the value of "$SHELL".
set shell=c:\COMMAND.COM shellquote= shellxquote= shellcmdflag=/c shellredir=>
" This is used only when the +eval feature is available.
if executable("cmd.exe")
   set shell=cmd.exe
endif