Problem:
Escaping logic for {subject} in ex cmd `:help {subject}` is done in a
messy 200+ lines C function which is hard to maintain and improve.
Solution:
Rewrite in Lua. Use `string.gsub()` instead of looping over characters
to improve clarity and add many more tests to be able to confidently
improve current code later on.
Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.
Closes https://github.com/neovim/neovim/issues/27004.
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
