patch 8.1.0098: segfault when pattern with z() is very slow commit https://github.com/vim/vim/commit/bcf9442307075bac40d44328c8bf7ea21857b138 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jun 23 14:21:42 2018 +0200 patch 8.1.0098: segfault when pattern with \z() is very slow Problem: Segfault when pattern with \z() is very slow. Solution: Check for NULL regprog. Add "nfa_fail" to test_override() to be able to test this. Fix that 'searchhl' resets called_emsg.