patch 7.4.741 Problem: When using += with ":set" a trailing comma is not recognized. (Issue 365) Solution: Don't add a second comma. Add a test. (partly by Christian Brabandt)

Tests for :set     vim: set ft=vim :

STARTTEST
:so small.vim
:set wildignore=*.png,
:set wildignore+=*.jpg
:$put =&wildignore
:/^Output goes here/+1,$w! test.out
:qa!
ENDTEST

Output goes here