Nvim doesn't expect a window-changing command on an created-window event.
autocmd WinNew * wincmd p
help help
- A snapshot for window 1000 is created.
- The window is split and the cursor changes to the new window 1001.
- The autocmd kicks in and switches back to 1000.
- The help buffer is opened.
- On closing the help window 1000, it tries to go back to the snapshotted window
which is... 1000.
- wp1000->w_buffer == NULL
- w_buffer is used by check_cursor()
- 🧨 -> 💥
Fixes https://github.com/neovim/neovim/issues/9773