patch 8.2.1576: Vim9: index() does not take "true" as argument Commit: https://github.com/vim/vim/commit/6c553f9c04a698ac2e19584f8ea8e2cb7cd98c80 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Sep 2 22:10:34 2020 +0200 patch 8.2.1576: Vim9: index() does not take "true" as argument Problem: Vim9: index() does not take "true" as argument. Solution: Use tv_get_bool_chk(). (closes https://github.com/vim/vim/issues/6823)