patch 8.1.0510: filter test fails when $LANG is C.UTF-8 commit https://github.com/vim/vim/commit/dcd71cbaedf75dd8e5c5a45c5c2e3ec7ee552dce Author: Bram Moolenaar <Bram@vim.org> Date: Sun Nov 4 14:40:47 2018 +0100 patch 8.1.0510: filter test fails when $LANG is C.UTF-8 Problem: Filter test fails when $LANG is C.UTF-8. Solution: Set 'helplang' to "en" for any C language. (Christian Brabandt, closes #3577)