Note: This only applies to ambiguous-width characters.

this works similar to <c-o> or <c-\><c-o> in insert mode

Problem:    Command overlaps with printed text in scrollback.
Solution:   Clear until end-of-line and use correct message chunk.
            (closes vim/vim#10765, closes vim/vim#10764)
https://github.com/vim/vim/commit/ecdc82e74e6a7e73d9067ece1d5eac33abfde5ed

N/A patches for version.c:

vim-patch:9.0.0070: using utfc_ptr2char_len() when length is negative

Problem:    Using utfc_ptr2char_len() when length is negative.
Solution:   Check value of length. (closes vim/vim#10760)
https://github.com/vim/vim/commit/4dc513a22c017b3061287deac74fa55f70a3214c

feat(tui): recognize keypad keys when using kitty keyboard protocol

* fix(test): screen.lua nil index
  When actual_rows and expected_rows are different avoid a nil index.
* fix(tui): resize at startup
  The deleted code is not needed after 402b4e8.
  It caused the condition to false positive when the function was called
  more than once before startup (first normal mode). Being itself what
  set the dimension and not the user, locking the size of the screen to
  an incorrect size.
  Make got_winch an int to mitigate: tui_grid_resize changing the size
  of the host terminal between the signal handler and the call to
  sigwinch_cb. Since the actual signal handler uv__signal_handle doesn't
  directly call the callback, the event loop does.

Fixes #17285
Fixes #15044
Fixes #11330

Problem:
- Since c57f6b28d71d #8519, sockets are created in ~/.local/… but XDG
  spec says: "XDG_RUNTIME_DIR: Must be on the local filesystem", which
  implies that XDG_STATE_DIR is potentially non-local.
- Not easy to inspect Nvim-created temp files (for debugging etc).

Solution:
- Store sockets in stdpath('run') ($XDG_RUNTIME_DIR).
- Establish "/tmp/nvim.user/" as the tempdir root shared by all Nvims.
- Make ok() actually useful.
- Introduce assert_nolog().

closes #3517
closes #17093