`nvim_get_option_value` and `nvim_set_option_value` better handle
unsetting local options. For instance, this is currently not possible:
vim.bo.tagfunc = nil
This does not work because 'tagfunc' is marked as "local to buffer" and
does not have a fallback global option. However, using :setlocal *does*
work as expected
:setlocal tagfunc=
`nvim_set_option_value` behaves more like :set and :setlocal (by
design), so using these as the underlying API functions beneath vim.bo
and vim.wo makes those two tables act more like :setlocal. Note that
vim.o *already* uses `nvim_set_option_value` under the hood, so that
vim.o behaves like :set.
Options formatted as a list of comma-separated key-value pairs may have
values that contain leading and trailing whitespace characters. For
example, the `listchars` option has a default value of
`"tab:> ,trail:-,nbsp:+"`. When converting this value to a lua table,
leading and trailing whitespace should not be trimmed.
Co-authored-by: Robert Hrusecky <robert.hrusecky@utexas.edu>
This closes#14677, but I also am a little unsure if there are times
where this may not be correct. However, this just changes the behavior
that even if `was_set` was false, we still get for
`nvim_win_get_option`.
