commit https://github.com/vim/vim/commit/dc0ccaee68ca24d10050117fbec757ad33590a17 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Oct 9 17:28:01 2016 +0200 patch 8.0.0027 Problem: A channel is closed when reading on stderr or stdout fails, but there may still be something to read on another part. Solution: Turn ch_to_be_closed into a bitfield. (Ozaki Kiichi)

" Common preparations for running tests.

" Make sure 'runtimepath' and 'packpath' does not include $HOME.
set rtp=$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after
if has('packages')
  let &packpath = &rtp
endif

" Only when the +eval feature is present. 
if 1
  " Make sure $HOME does not get read or written.
  let $HOME = '/does/not/exist'
endif