Problem:  Cannot detect overstrike mode in Cmdline mode
Solution: Make mode() return "cr" for overstrike

closes: vim/vim#13569

https://github.com/vim/vim/commit/d1c3ef1f47c87d1da056c56564e1985fe6f2931d

Problem:
crash from
  set complete+=f
  open a empty buffer
  C-N

Solution:
make sure the buffer name is valid.

regression from ae4ca4edf89ece433b61e8bf92c412298b58d9ea

Problem:    TextChanged does not trigger after TextChangedI.
Solution:   Store the tick separately for TextChangedI. (Christian Brabandt,
            closes vim/vim#8968, closes vim/vim#8932)

https://github.com/vim/vim/commit/db3b44640d69ab27270691a3cab8d83cc93a0861

Co-authored-by: Christian Brabandt <cb@256bit.org>

Previously, when using foldmethod=indent, inserting an unindented line
would inadvertently open closed folds below it.
As a performance improvement, folds were only updated once, across all
lines, after Insert mode was exited.

Now, the performance improvement is no longer being used when
foldmethod=indent, so folds are updated multiple times during Insert
mode, but only across the lines that are changing, which preserves the
folds (and their open/close states) instead of recreating them.

Problem:
nvim_parse_cmd() in pcall() may show an error message (side-effect):

    :lua pcall(vim.api.nvim_parse_cmd, vim.fn.getcmdline(), {})
    E16: Invalid range

Solution:
Avoid emsg() in the nvim_parse_cmd() codepath.

- refactor(api): add error message output parameter to get_address()
- fix: null check emsg() parameter
- refactor: remove emsg_off workaround from do_incsearch_highlighting()
- refactor: remove emsg_off workaround from cmdpreview_may_show()
- refactor: remove remaining calls to emsg() from parse_cmd_address() and get_address()
- (refactor): lint set_cmd_dflall_range()
- refactor: addr_error() - move output parameter to return value

Fix #20339

TODO:

These are the functions called by `get_address()`:

```
nvim_parse_cmd() -> parse_cmdline() -> parse_cmd_address() -> get_address()
    skipwhite()
    addr_error()
    qf_get_cur_idx()
    qf_get_cur_valid_idx()
    qf_get_size()
    qf_get_valid_size()
    mark_get()
    mark_check()
    assert()
    skip_regexp()
    magic_isset()
>   do_search()
>   searchit()
    ascii_isdigit()
    getdigits()
    getdigits_int32()
    compute_buffer_local_count()
    hasFolding()
```

From these functions, I found at least two that call emsg directly:
- do_search()
  - seems to be simple to refactor
- searchit()
  - will be more challenging because it may generate multiple error messages,
    which can't be handled by the current `errormsg` out-parameter.
    For example, it makes multiple calls to `vim_regexec_multi()` in a loop that
    possibly generate error messages, and later `searchit()` itself may generate
    another one:
    - https://github.com/neovim/neovim/blob/c194acbfc479d8e5839fa629363f93f6550d035c/src/nvim/search.c#L631-L647
    - https://github.com/neovim/neovim/blob/c194acbfc479d8e5839fa629363f93f6550d035c/src/nvim/search.c#L939-L954

---------

Co-authored-by: Justin M. Keyes <justinkz@gmail.com>