Problem with opening new files when `:help` window is opened

[KriBielinski]

Description

While opening and closing files and :help buffer in a specific order, after then opening a new file using nvim-tree, the new file is open in a split window instead of replacing the :help buffer.
The problem can be replicated using just the standard configuration.

Neovim version

NVIM v0.11.0-dev-1079+g7bf3a616e1                                                                                                   
Build type: Release                                                                                                                 
LuaJIT 2.1.1727870382

Operating system and version

Distro: Linux Mint 21 Vanessa, base: Ubuntu 22.04 jammy

Windows variant

No response

nvim-tree version

28eac28

Clean room replication

vim.g.loaded_netrw = 1
vim.g.loaded_netrwPlugin = 1

vim.cmd([[set runtimepath=$VIMRUNTIME]])
vim.cmd([[set packpath=/tmp/nvt-min/site]])
local package_root = "/tmp/nvt-min/site/pack"
local install_path = package_root .. "/packer/start/packer.nvim"
local function load_plugins()
  require("packer").startup({
    {
      "wbthomason/packer.nvim",
      "nvim-tree/nvim-tree.lua",
      "nvim-tree/nvim-web-devicons",
      -- ADD PLUGINS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
    },
    config = {
      package_root = package_root,
      compile_path = install_path .. "/plugin/packer_compiled.lua",
      display = { non_interactive = true },
    },
  })
end
if vim.fn.isdirectory(install_path) == 0 then
  print("Installing nvim-tree and dependencies.")
  vim.fn.system({ "git", "clone", "--depth=1", "https://github.com/wbthomason/packer.nvim", install_path })
end
load_plugins()
require("packer").sync()
vim.cmd([[autocmd User PackerComplete ++once echo "Ready!" | lua setup()]])
vim.opt.termguicolors = true
vim.opt.cursorline = true

-- MODIFY NVIM-TREE SETTINGS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
_G.setup = function()
  require("nvim-tree").setup({})
end

-- UNCOMMENT this block for diagnostics issues, substituting pattern and cmd as appropriate.
-- Requires diagnostics.enable = true in setup.
--[[
vim.api.nvim_create_autocmd("FileType", {
  pattern = "lua",
  callback = function()
    vim.lsp.start {
      name = "my-luals",
      cmd = { "lua-language-server" },
      root_dir = vim.loop.cwd(),
    }
  end,
})
]]

Steps to reproduce

1. nvim -nu /tmp/nvt-min.lua to open Neovim
2. :NvimTreeOpen to open nvim-tree. It will appear in a split on the left.
3. Navigate to any file inside of nvim-tree and than press Enter to open it. The file will appear on the window to the right.
4. :help to open the help window. It should appear in a split window next to the opened file.
5. Navigate to the window with the file opened in step 3 (using <C-w>+h/j/k/l) and close that window with :q
6. Navigate to nvim-tree window (using <C-w>+h/j/k/l)
7. Open any file (doesn't have to be the same as before) as described in step 3

Expected behavior

The newly opened file should replace the :help buffer (as it would do with any other buffer) but instead the new file openes in a vertical split next to the :help window. Also if instead of opening the file in step 7 you instead press <C-x> to attempt to open the file in horizontal split, the file still opens in vertical split.

Actual behavior

The newly opened file opens in a vertical split (either when opening using Enter or <C-x>)

[alex-courtis]

Default vim behaviour is help splitting horizontally above all windows.

Have you got any other configuration that places the help window (I do https://github.com/alex-courtis/arch/blob/735510bdd95635e129ce34e072f9f0da4874a977/config/nvim/lua/amc/windows.lua#L144)

This doesn't address the issue though.

[alex-courtis]

nvim-tree won't open files in windows with "special" buffers.

See :help nvim-tree.actions.open_file.window_picker.exclude

            {
              filetype = {
                "notify",
                "packer",
                "qf",
                "diff",
                "fugitive",
                "fugitiveblame",
              },
              buftype = {
                "nofile",
                "terminal",
                "help",
              },
            }

This could be documented better.

[KriBielinski]

Hello @alex-courtis,

nvim-tree won't open files in windows with "special" buffers.

Well, this doesn't seem to be exactly true as I can also create a sequence of actions like this:

1. nvim -nu /tmp/nvt-min.lua
2. :help to open help and then <C-w>o to make :help the only window
3. :NvimTreeOpen to open nvim-tree and open any file by navigating to it and using Enter

And now the newly opened file does actually replace the :help buffer.

But back to my original problem, like you have written in your last comment I have removed to help buffer from the list of excluded buffers by adding this to my nvim-tree configuration:

actions = {
  open_file = {
    window_picker = {
      exclude = {
        buftype = {
          "nofile",
          "terminal",
          --"help" -- remove :help from excluded list
        }
      },
    },
  },
}

and now everything works precisely as I expected it to. So thank you very much for help, I have solved the problem which I originally had at the beginning.

Well, since my problem is solved, should I close this issue now? I don't know, this my first issue ever on GitHub.

[alex-courtis]

Well, since my problem is solved, should I close this issue now? I don't know, this my first issue ever on GitHub.

Many thanks for raising and please do continue.

I'm moving this to a Q/A discussion, so that others may benefit.

In the future, if you have a general question, please ask in there.