patch 8.1.0505: filter command test may fail if helplang is not set commit https://github.com/vim/vim/commit/bd9a0c611ce08f8dce033537bc2f110987b99802 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Nov 3 19:00:14 2018 +0100 patch 8.1.0505: filter command test may fail if helplang is not set Problem: Filter command test may fail if helplang is not set. Solution: Set 'helplang' for the test. (James McCoy, closes https://github.com/vim/vim/issues/3591)

For information about installation of Farsi fonts and Vim usage in Farsi mode,
refer to the Farsi help file by typing ":help farsi" in Vim.