commit https://github.com/vim/vim/commit/da94fdf2588b3910d38e477a755748ce2c6d2e66 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Mar 3 18:09:10 2016 +0100 patch 7.4.1482 Problem: "timeout" option not supported on ch_send*() and ch_eval*(). Solution: Get and use the timeout option from the argument.

" 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