commit https://github.com/vim/vim/commit/2b2b8ae5ab37b04584633c469265d85825166905 Author: Bram Moolenaar <Bram@vim.org> Date: Tue May 24 19:59:51 2016 +0200 patch 7.4.1841 Problem: The code to reallocate the buffer used for quickfix is repeated. Solution: Move the code to a function. (Yegappan Lakshmanan, closes https://github.com/vim/vim/issues/831)

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