fix(api): nvim_buf_call() from expression for window in non-current tabpage #42352

Problem:
- nvim_buf_call() aborts (assert) when called from an expression evaluated
  for a window in another tabpage ('foldexpr', 'statusline'), because
  `curwin` is not in `curtab`.
- After it returns, `curwin` is wrong if it switched windows.
- `vim._with{win=…, keepcwd=true}` does not undo `:lcd` if `win` is in
  another tabpage.

Solution:
- Allow `curwin` outside `curtab`, and restore if it was outside
  `curtab` at `ctx_switch()`.
- Find the target window in any tabpage when restoring its dirs.

0 files changed, 0 insertions, 0 deletions