patch 8.2.4166: undo synced when switching buffer in another window Commit: https://github.com/vim/vim/commit/e615db06046312e74886fa1ef98feb5a9db2a7c3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jan 20 21:00:54 2022 +0000 patch 8.2.4166: undo synced when switching buffer in another window Problem: Undo synced when switching buffer in another window. Solution: Do not sync undo when not needed. (closes https://github.com/vim/vim/issues/9575)