config merging does not convert vim.NIL to nil

[wookayin]

FAQ

• [X] I have checked the FAQ and it didn't resolve my problem.

Issues

• [X] I have checked existing issues and there are no open or closed issues with the same problem.

Neovim Version

v0.7.0-dev+963-g082ff2190

Minimal reproducible full config

cmp version: dbc7229

minimal.vim

if has('vim_starting')                                                                                                                                 
  set encoding=utf-8                                                                                                                                   
endif                                                                                                                                                  
scriptencoding utf-8                                                                                                                                   
                                                                                                                                                       
if &compatible                                                                                                                                         
  set nocompatible                                                                                                                                     
endif                                                                                                                                                  
                                                                                                                                                       
let s:plug_dir = expand('/tmp/plugged/vim-plug')                                                                                                       
if !filereadable(s:plug_dir .. '/plug.vim')                                                                                                            
  execute printf('!curl -fLo %s/autoload/plug.vim --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim', s:plug_dir)      
end                                                                                                                                                    
                                                                                                                                                       
execute 'set runtimepath+=' . s:plug_dir                                                                                                               
call plug#begin(s:plug_dir)                                                                                                                            
Plug 'hrsh7th/nvim-cmp'
Plug 'hrsh7th/cmp-buffer'
Plug 'hrsh7th/vim-vsnip'
"Plug 'gelguy/wilder.nvim'
"Plug 'romgrk/fzy-lua-native'
call plug#end()
PlugInstall | quit

" Setup global configuration. More on configuration below.
lua << EOF
local cmp = require "cmp"
local cmp_types = require('cmp.types.cmp')

cmp.setup {
  snippet = {
    expand = function(args)
      vim.fn["vsnip#anonymous"](args.body)
    end,
  },

  mapping = {
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-y>'] = cmp.config.disable,
    ['<C-e>'] = cmp.mapping.close(),
    ['<Down>'] = cmp.mapping.select_next_item({ behavior = cmp_types.SelectBehavior.Select }),
    ['<Up>'] = cmp.mapping.select_prev_item({ behavior = cmp_types.SelectBehavior.Select }),
    ['<C-n>'] = cmp.mapping.select_next_item({ behavior = cmp_types.SelectBehavior.Insert }),
    ['<C-p>'] = cmp.mapping.select_prev_item({ behavior = cmp_types.SelectBehavior.Insert }),
    ['<CR>'] = cmp.mapping.confirm({ select = false }),
    ['<Tab>'] = {
      i = function(fallback)  -- see GH-231, GH-286
        if cmp.visible() then cmp.select_next_item()
        elseif has_words_before() then cmp.complete()
        else fallback() end
      end,
      c = cmp.config.disable, -- see GH-880
    },
    ['<S-Tab>'] = {
      i = function(fallback)
        if cmp.visible() then cmp.select_prev_item()
        else fallback() end
      end,
      c = cmp.config.disable,
    },
  },

  sources = {
    { name = "buffer" },
  },
}

Note the config ['<Tab>'] = { .... c = cmp.config.disable } to disable TAB mappings in the command line.

Description

<Tab> keys are broken again. When pressing it, an error occurs.

Steps to reproduce

Press <Tab> in the command-line.

Expected behavior

Actual behavior

E5108: Error executing lua /tmp/plugged/vim-plug/nvim-cmp/lua/cmp/core.lua:113: attempt to call a userdata value
stack traceback:
        /tmp/plugged/vim-plug/nvim-cmp/lua/cmp/core.lua:113: in function 'on_keymap'
        /tmp/plugged/vim-plug/nvim-cmp/lua/cmp/core.lua:145: in function 'callback'
        /tmp/plugged/vim-plug/nvim-cmp/lua/cmp/utils/keymap.lua:114: in function </tmp/plugged/vim-plug/nvim-cmp/lua/cmp/utils/keymap.lua:108>
        /tmp/plugged/vim-plug/nvim-cmp/lua/cmp/utils/keymap.lua:244: in function </tmp/plugged/vim-plug/nvim-cmp/lua/cmp/utils/keymap.lua:243>

Additional context

This happened due to recent breaking changes in the keymappings.

Can we completely disable and prevent cmp from taking <cmp> keymaps via the "delegation" or "fallback" mechanism? As in #590, I absolutely don't want the following cmap to exist when keymaps are configured to be disabled:

c  <Tab>       * <Cmd>call v:lua.cmp.utils.keymap.set_map(1)<CR> 

[Shougo]

Well...

  c = cmp.config.disable, -- see GH-880

The mapping config is needed? As I know the default mappings are removed.

[wookayin]

Hi @Shougo, thanks for the comment! After today's breaking change #895, this is not needed any more. I tried removing this line, and indeed no more errors.

However, that specific line was necessary, until today; four days ago #880 required us to explicitly disable it (and now the default mapping has been removed).

Even with the explicit disabling, it should behave the same.

[Shougo]

OK. The main problem seems cmp.config.disable does not work.

[wookayin]

Exactly! cmp.config.disable = vim.NIL, which does not evaluate to false in lua.

[hrsh7th]

I think you should simply remove c = cmp.config.disable.

But it's like a bug. I'll check it.