bug: conceallevel changes when opening a new split window

[maxh]

Did you check the docs and existing issues?

• I have read the docs
• I have searched the existing issues

Neovim version (nvim -v)

NVIM v0.8.0 Build type: Release LuaJIT 2.1.0-beta3

Operating system/version

13.2.1 (22D68)

Describe the bug

When I split a new window when oil is open, the existing window has its conceallevel changed from 3 to 0.

Steps To Reproduce

• nvim -u ~/tmp/repro.lua -V1
• <_>
• <C-w><C-v>
• :verbose set conceallevel

  conceallevel=0                                                                                                                                                                   
        Last set from ~/.local/share/nvim/site/pack/packer/start/oil.nvim/lua/oil/init.lua line 888  

Seems to be done here:

oil.nvim/lua/oil/init.lua

Line 888 in 873ea3b

vim.api.nvim_win_set_option(0, k, opt)

Expected Behavior

I would expect the conceallevel in the original window to remain unchanged.

Directory structure

I opened my config dir (using the repro config):

lua/
plugin/
queries/
spell/
init.lua

Repro

-- save as repro.lua
-- run with nvim -u repro.lua
-- DO NOT change the paths
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "runtime", "cache" }) do
	vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end

-- bootstrap lazy
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
	vim.fn.system({
		"git",
		"clone",
		"--filter=blob:none",
		"--single-branch",
		"https://github.com/folke/lazy.nvim.git",
		lazypath,
	})
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
	"folke/tokyonight.nvim",
	{
		"stevearc/oil.nvim",
		config = function()
			require("oil").setup({})
		end,
	},
}
vim.keymap.set("n", "-", require("oil").open, { desc = "Open parent directory" })
require("lazy").setup(plugins, {
	root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")
-- add anything else here

Did you check the bug with a clean config?

• I have confirmed that the bug reproduces with nvim -u repro.lua using the repro.lua file above.

[stevearc]

Fixed!