commit https://github.com/vim/vim/commit/83162468b3c8722fffea033d3de144cd4191472a Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jan 28 23:10:07 2016 +0100 patch 7.4.1194 Problem: Compiler warning for not using return value of fwrite(). Solution: Return OK/FAIL. (Charles Campbell)

" 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