commit https://github.com/vim/vim/commit/2455c4ede8d4ff6f0754977b548708eec08869eb Author: Bram Moolenaar <Bram@vim.org> Date: Tue Sep 15 18:29:39 2015 +0200 patch 7.4.870 Problem: May get into an invalid state when using getchar() in an expression mapping. Solution: Anticipate mod_mask to change. (idea by Yukihiro Nakadaira)