Setting mapping in `cmp.setup.cmdline({'/', '?'}, {` prevents command tab completion from working after search

[newgear0727]

FAQ

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

Announcement

• [X] I have checked Breaking change announcement.

Minimal reproducible full config

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/cmp-nvim-lsp'
Plug 'hrsh7th/cmp-cmdline'
Plug 'neovim/nvim-lspconfig'

Plug 'hrsh7th/cmp-path'
Plug 'hrsh7th/cmp-calc'

call plug#end()
PlugInstall | quit

" Setup global configuration. More on configuration below.
lua << EOF
local cmp = require "cmp"
cmp.setup {
  mapping = {
    ['<CR>'] = cmp.mapping.confirm({ select = true })
  },
  sources = cmp.config.sources({
    { name = "nvim_lsp" },
    { name = "buffer" },
  }),
}
local capabilities = require('cmp_nvim_lsp').default_capabilities()

cmp.setup.cmdline({'/', '?'}, {
    -- setting mapping causes the issue of :e %^I after / search
    mapping = cmp.mapping.preset.cmdline(),
    sources = {
        { name = 'buffer' }
    }
})
EOF

Description

When mapping = cmp.mapping.preset.cmdline(), is provided to the /, ? cmp cmdlines, after searching once tab completion in the vim commandline stops working and prints ^I instead. If you remove the mapping then the problem won't trigger.

Steps to reproduce

1. Open some file with nvim using attached minimal config
2. Verify that :e %<tab> will actually tab-expand % to current filename.
3. Perform search using /foo<CR> or equivalent; verify that :e %<tab> will not work anymore and instead, print ^I per tab invocation.
4. Comment out mapping line in example config and verify (3) above cannot be reproduced.

Expected behavior

:e %<tab> will expand current filename after performing at least one search

Actual behavior

:e %<tab> will expand to :e %^I which is not expected.

Additional context

I don't know the significance of the mapping attribute for the search cmdline config but I merely copy-pasted it from the reference manual/README.

[devpaps]

I also have this bug.

[rhaidiz]

I also have the same issue but I found this answer suggesting to specify the cmdline source option in a different way:

cmp.setup.cmdline(':', {
  sources = {
    {
      name = 'cmdline',
      option = {
        ignore_cmds = {}
      }
    }
  } 
})

I tried it and so far it seems to be working but haven't had a chance to test it extensively.

[lucy]

@rhaidiz Adding that doesn't do anything for me. Builtin cmdline completion still breaks after using completion in / or ? once.

[entropitor]

Yeah indeed, that snippet made it work for me on editor open but it breaks after searching.

I tried manually setting mappings for / and ? but I don't seem to be able to find the necessary code to get it to even work 😅

My guess is that the mappings from ? and / are also used for : once it has been triggered once, as when I add mapping = cmp.mapping.preset.cmdline() to the : cmdline option, it breaks from the start of the editor.

[demitau]

I also have this bug

[hrsh7th]

I'm sorry, but this is the specification.

In Vim's cmdline mode, key mappings for : and / are not separated by namespace, so enabling cmp for / also enables key mappings for :. The only solution is to enable cmp-cmdline for :. However, this may not achieve full compatibility with existing cmdline behavior.

At this point, there is no complete solution and there are trade-offs. Please understand.

Workaround.

cmp.setup.cmdline(':', {
  autocomplete = false,
  sources = {
    { name = 'cmdline' }
  }
})

[cpkio]

I don't think I have this behaviour, completion in : works fine after /. But I've found another bug: completion menu appears but no selection can be made if the command string has no space in it. :%s Some — I will get a working completion menu (it's not a valid search/replace string still). On :%s/Some completion menu will appear but nothing can be selected. mapping = cmp.mapping.preset.cmdline(), nothing fancy here.

[ehbLuca]

this workaround works for me: found here vim.keymap.set('c', '', '', { silent = false }) -- to fix cmp

[camoz]

@ehbLuca You should use code formatting to paste code, in your snippet the LHS and RHS of the mapping got eaten. Here is the full mapping:

vim.keymap.set('c', '<tab>', '<C-z>', { silent = false }) -- to fix cmp

Can confirm this works for me.

[vehlwn]

I think this behavior should be more obvious from the readme than one line at the bottom of FAQ.

https://github.com/hrsh7th/nvim-cmp/blob/ae644feb7b67bf1ce4260c231d1d4300b19c6f30/doc/cmp.txt#L1064