commit https://github.com/vim/vim/commit/e5a8f35b4286135f3469f3b00a6c2220553d9658 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Aug 16 21:30:54 2016 +0200 patch 7.4.2220 Problem: printf() gives an error when the argument for %s is not a string. (Ozaki Kiichi) Solution: Behave like invoking string() on the argument. (Ken Takata)