commit https://github.com/vim/vim/commit/d29459baa61819e59961804ed258efac5733ec70 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Aug 26 22:29:11 2016 +0200 patch 7.4.2263 Problem: :filter does not work for many commands. Can only get matching messages. Solution: Make :filter work for :command, :map, :list, :number and :print. Make ":filter!" show non-matching lines.

" 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