patch 9.0.1763: crash when passing invalid buffer to undotree() Commit: https://github.com/vim/vim/commit/ab9f2ecfd4ecaf74eeed0e5ec41355589af3ec8f Author: zeertzjq <zeertzjq@outlook.com> Date: Sun Aug 20 18:35:10 2023 +0200 patch 9.0.1763: crash when passing invalid buffer to undotree() Problem: crash when passing invalid buffer to undotree() Solution: Use get_buf_arg() instead of tv_get_buf_from_arg(). closes: #12862 closes: #12830 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: zeertzjq <zeertzjq@outlook.com>