(Neo)Vim 'w' behaves like 'W' in a certain scenario

[Zeta611]

Issue
Vim word movements like 'w', 'e', 'b', etc. suddenly behave like their capital counterparts 'W', 'E', 'B', etc., when a quickfix list pops out and if the cursor is on the end-of-a-line-}.
This issue has been nagging me for a few years, and I finally had a time to investigate it.

iskeyword seems to be fine:

 iskeyword=@,48-57,_,192-255,:

This issue is always reproducible with the following minimal.vim & minimal.tex on my Macs.

minimal.vim

let &runtimepath  = '~/.local/share/nvim/plugged/vimtex,' . &runtimepath
let &runtimepath .= ',~/.local/share/nvim/plugged/vimtex/after'

minimal.tex

% Below 'articl' is an intended typo
\documentclass{articl}
\begin{document}
\TeX
\end{document}

Commands/Input
Put the cursor on the closing curly bracket } in {acticl}.
Then start a continuous compile mode via \ll.

Observed Behaviour
The missing 'e' opens the quickfix list, and if you try to move using w, it would behave like W.

This also breaks a 3rd party plugin like easymotion, only showing the starts of Words (delimited by spaces).

Expected Behaviour
It should still act like a normal w(, e, b, etc.).

Output from VimtexInfo

System info
  OS: Mac OS X 10.15.3 (19D76)
  Vim version: NVIM v0.4.3
  Has clientserver: true
  Servername: /var/folders/cs/7bfzsfzx7bn67bhxn0pgzk1w0000gn/T/nvim72gwdA/0

vimtex project: minimal
  base: minimal.tex
  root: /Users/jay/vimtex
  tex: /Users/jay/vimtex/minimal.tex
  out: /Users/jay/vimtex/minimal.pdf
  log: /Users/jay/vimtex/minimal.log
  aux: /Users/jay/vimtex/minimal.aux
  fls: /Users/jay/vimtex/minimal.fls
  compiler: latexmk
    backend: nvim
    output: /var/folders/cs/7bfzsfzx7bn67bhxn0pgzk1w0000gn/T/nvim72gwdA/1
    configuration: 
      continuous: 1
      callback: 1
      latexmk options:
        -verbose
        -file-line-error
        -synctex=1
        -interaction=nonstopmode
      latexmk engine: -pdf
  viewer: General
  qf: LaTeX logfile
    config: 
      packages: 
        default: 1
      default: 1
  document class: article

Output from chechhealth

health#vimtex#check
========================================================================
## vimtex
  - OK: Vim version should have full support!
  - OK: General viewer should work properly!
  - WARNING: pstree is not available
    - ADVICE:
      - vimtex#view#reverse_goto is better if pstree is available.
  - WARNING: Compiler callbacks will not work!
    - ADVICE:
      - `neovim-remote` / `nvr` is required for callbacks to work with neovim
      - Please also set |g:vimtex_compiler_progname| = 'nvr'
      - For more info, see :help |vimtex-faq-neovim|

health#nvim#check
========================================================================
## Configuration
  - OK: no issues found

## Performance
  - OK: Build type: Release

## Remote Plugins
  - OK: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=^H
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~
  - INFO: $TERM_PROGRAM='iTerm.app'
  - INFO: $COLORTERM='truecolor'

## tmux
  - OK: escape-time: 0ms
  - INFO: $TERM: tmux-256color

health#provider#check
========================================================================
## Clipboard (optional)
  - OK: Clipboard tool found: pbcopy

## Python 2 provider (optional)
  - INFO: pyenv: Path: /usr/local/Cellar/pyenv/1.2.16/libexec/pyenv
  - INFO: pyenv: $PYENV_ROOT is not set. Infer from `pyenv root`.
  - INFO: pyenv: Root: /Users/jay/.pyenv
  - WARNING: No Python executable found that can `import neovim`. Using the first available executable for diagnostics.
  - ERROR: Python provider error:
    - ADVICE:
      - provider/pythonx: Could not load Python 2:
          /Users/jay/.pyenv/shims/python2 does not exist: pyenv: python2: command not found
          
          The `python2' command exists in these Python versions:
          2.7.17
          2.7.17/envs/neovim-python2
          neovim-python2
          
          
          /Users/jay/.pyenv/shims/python2.7 does not exist: pyenv: python2.7: command not found
          
          The `python2.7' command exists in these Python versions:
          2.7.17
          2.7.17/envs/neovim-python2
          neovim-python2
          
          
          python2.6 not found in search path or not executable.
          /Users/jay/.pyenv/shims/python is Python 3.8 and cannot provide Python 2.
  - INFO: Executable: Not found

## Python 3 provider (optional)
  - INFO: pyenv: Path: /usr/local/Cellar/pyenv/1.2.16/libexec/pyenv
  - INFO: pyenv: $PYENV_ROOT is not set. Infer from `pyenv root`.
  - INFO: pyenv: Root: /Users/jay/.pyenv
  - WARNING: No Python executable found that can `import neovim`. Using the first available executable for diagnostics.
  - ERROR: Python provider error:
    - ADVICE:
      - provider/pythonx: Could not load Python 3:
          /Users/jay/.pyenv/shims/python3 does not have the "neovim" module. :help |provider-python|
          /usr/local/bin/python3.7 does not have the "neovim" module. :help |provider-python|
          python3.6 not found in search path or not executable.
          python3.5 not found in search path or not executable.
          python3.4 not found in search path or not executable.
          python3.3 not found in search path or not executable.
          /Users/jay/.pyenv/shims/python does not have the "neovim" module. :help |provider-python|
  - INFO: Executable: Not found

## Ruby provider (optional)
  - INFO: Ruby: ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]
  - INFO: Host: /Users/jay/.rbenv/shims/neovim-ruby-host
  - OK: Latest "neovim" gem is installed: 0.8.1

## Node.js provider (optional)
  - INFO: Node.js: v13.7.0
  - INFO: Neovim node.js host: /usr/local/lib/node_modules/neovim/bin/cli.js
  - OK: Latest "neovim" npm/yarn package is installed: 4.8.0

[lervag]

I'm sorry, but I can't reproduce. Could you make it more clear what you mean by:

Commands/Input
Put the cursor on the closing curly bracket } in {acticl}.
Then start a continuous compile mode via \ll.

Observed Behaviour
The missing 'e' opens the quickfix list, and if you try to move using w, it would behave like W.

OK, I make a minimal vimrc file like this:

set nocompatible
let &rtp = '/path/to/vimtex,' . &rtp
let &rtp .= ',/path/to/vimtex/after'
filetype plugin indent on
syntax enable

Then I open the test file with vim --servername VIM -u test.vim test.tex or nvim --servername -u test.vim test.tex. I move to the closing bracket, then do \ll. I observe that the quickfix window opens due to the error. Then I type w, and the cursor moves to the next line as expected. The next w moves to b in \begin, also as expected.

Am I missing the point here?

[Zeta611]

That's odd, since I did exactly the same on my colleague's Mac and could reproduce the bug.
If I type w, the cursor moves to the next line's \, and another w moves me to the next line's \ before TeX, instead of bringing me to the b of begin.

My colleague's Mac didn't have Neovim/Vimtex installed, so I freshed installed it using brew install neovim & installed Vimtex using vim-plug (which was also fresh-installed).
I placed minimal.vim and minimal.tex under /tmp/vimtex and opened it using nvim -u minimal.vim minimal.tex.

If relevant, I'm on macOS Catalina 10.15.2 using zsh 5.7.1.

+The following shows what I did on the new Mac:

[vihuna]

I have tried in Debian 10 with default applications (Bash shell, gnome-terminal, ...), but also I have tried with tmux and zhs in Ubuntu 18.04, and I can't reproduce it. w and W worked as expected, following all your instructions.
Can it be something related to macOS or localization?
Also, although it may have nothing to do with this strange motion behavior, it seems the :VimtexInfo does not correspond to the file minimal.tex (document class: article; packages: expl3, ... ,xparse).

[Zeta611]

@Bancini Regarding the :VimtexInfo, it was my mistake. It was done using my custom vim settings. I updated the info.

[Zeta611]

• I also noticed that ctrl-n and ctrl-p no longer autocompletes normally, but it prompts "Scanning tags." The autocompletion that pops up blindly shows all the words used in a document, not a normal 'smart' suggestions..

[lervag]

Yes, ctrl-n and ctrl-p are not mapped in vimtex and is not related to vimtex. By default, they do keyword completion, please read :help i_CTRL-N. So this is as expected.

I am sorry to say I can't really help here because I can't reproduce. Could you try to either upgrade or downgrade your neovim version?

Perhaps @clason might have time to test this, I know he uses a Mac.

[clason]

Indeed, I can reproduce this (neovim nightly on Catalina) -- the w issue, I mean. Seeing as this is likely a neovim bug, it would be good to bisect it.

[lervag]

Ok, good! That's progress! Can you reproduce the issue in Vim as well?

[clason]

No, because I apparently forgot how to use vim (the minimal vimrc doesn't work on vim for me), but at least I could reproduce on Linux (openSUSE Tumbleweed, again neovim head).

[Zeta611]

@lervag Vim does work fine! So apparently this is a Neovim bug..

[lervag]

No, because I apparently forgot how to use vim (the minimal vimrc doesn't work on vim for me), ...

Haha :)

... but at least I could reproduce on Linux (openSUSE Tumbleweed, again neovim head).

That's interesting. I've tested with NVIM v0.5.0-132-g83b6d9f19, which I guess is not the nightly build. But it is quite recent. Which version are you on that fails? At least this should give us some bounds for a bisection, right?

[clason]

It's NVIM v0.5.0-d9657b3ae, but OP is on the last release (0.4.3), so it has to be quite back. But maybe it's tied to a system library.

@lervag How did you install nvim? Built yourself from the repo or via nightly appimage / distropackage?

[Zeta611]

@clason I installed it using Homebrew package manger for Mac. I've been having this issue for quite a long time--at least a year.

[lervag]

I'm on Arch Linux and use the neovim-git package from AUR. It should be a recent version. So I agree, it seems it may be related to a system library. Not quite sure how to debug this...