patch 8.1.0540: may evaluate insecure value when appending to option commit https://github.com/vim/vim/commit/247bb7e43b47eb8407a1111bed60b61aceda52ad Author: Bram Moolenaar <Bram@vim.org> Date: Tue Nov 20 14:27:07 2018 +0100 patch 8.1.0540: may evaluate insecure value when appending to option Problem: May evaluate insecure value when appending to option. Solution: Set the secure flag when changing an option that was previously set insecurely. Also allow numbers for the characters from 'spelllang' that are used for LANG.vim.