BUG: fuzzy_finder_mappings aren't normalized and don't respect use_default_mappings

[Kaiser-Yang]

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Neovim Version (nvim -v)

0.10.1

Operating System / Version

WSL2 + Ubuntu 22.04 LTS

Describe the Bug

I've set use_default_mappings = false, but the mapping for input and filter popup is not disable, I can still see the mappings:

Screenshots, Traceback

No response

Steps to Reproduce

1. Set use_default_mapping=false
2. Use / to open filter
3. The key bindings <c-n> and <c-p> is still working

Expected Behavior

Disable these mappings.

Your Configuration

-- DO NOT change the paths and don't remove the colorscheme
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "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", "https://github.com/folke/lazy.nvim.git", lazypath, })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "folke/tokyonight.nvim",
  -- add any other plugins here
}

local neotree_config = {
  "nvim-neo-tree/neo-tree.nvim",
  dependencies = { "MunifTanjim/nui.nvim", "nvim-tree/nvim-web-devicons", "nvim-lua/plenary.nvim" },
  cmd = { "Neotree" },
  keys = {
    { "<Leader>e", "<Cmd>Neotree<CR>" }, -- change or remove this line if relevant.
  },
  opts = {
    -- Your config here
    -- ...
use_default_mapping=false,
            filesystem                = {
                window = {
                    mappings = {
                        ['/'] = 'fuzzy_finder',
                    },
                    fuzzy_finder_mappings = {
                        ["<c-j>"] = "move_cursor_down",
                        ["<c-k>"] = "move_cursor_up",
                        -- ['<c-n>'] = 'noop' -- this will give me a warning 'noop' command a niv value
                    },
                },
}
  },
}

table.insert(plugins, neotree_config)
require("lazy").setup(plugins, {
  root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")

[Kaiser-Yang]

I found that the merge_config for defaults and user's configurations did not use to_lower or to_upper make all the key with <> as lower or upper letters.

This will make weired behaviors, because in nvim, <c-n>, <C-n>, <C-N> and <c-N> are all the same, but in lua they are different strings. In the default keymappings use <C-n> for cursor down, which means I must use <C-n> = 'xxx', because <c-n> will appear before <C-n> in a table, the key will be override by the default <C-n>.

BTW, use <C-n> = 'noop' will disable the <c-n>, although it will give me the warning every time I use fuzzy finder.