commit https://github.com/vim/vim/commit/2faa29f896252073b53f387406109e331fbbe5f8 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jan 23 23:02:34 2016 +0100 patch 7.4.1161 Problem: ":argadd" without argument is supposed to add the current buffer name to the arglist. Solution: Make it work as documented. (Coot, closes https://github.com/vim/vim/issues/577)

Test for ":options".

STARTTEST
:so small.vim
:let caught = 'ok'
:try
  :options
:catch 
  :let caught = v:throwpoint . "\n" . v:exception
:endtry
:buf 1
:$put =caught
:"
:" Test that changing 'path' keeps two commas.
:set path=foo,,bar
:set path-=bar
:set path+=bar
:$put =&path
:/^result/,$w! test.out
:qa!
ENDTEST

result