patch 8.1.0488: using freed memory in quickfix code commit https://github.com/vim/vim/commit/9f84ded38b62c82a4ee57b54f403b1b185ed8170 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Oct 20 20:54:02 2018 +0200 patch 8.1.0488: using freed memory in quickfix code Problem: Using freed memory in quickfix code. (Dominique Pelle) Solution: Add the quickfix_busy() flag to postpone deleting quickfix lists until it is safe. (Yegappan Lakshmanan, closes #3538)