Error in inlay hints when enabled not in current window

[echasnovski]

Problem

When inlay hints are enabled in case target buffer is not in current window, there is the following error:

Error in decoration provider vim_lsp_inlayhint.win:
Error executing lua: ...CVKwkT/usr/share/nvim/runtime/lua/vim/lsp/inlay_hint.lua:320: assertion failed!
stack traceback:
        [C]: in function 'assert'
        ...CVKwkT/usr/share/nvim/runtime/lua/vim/lsp/inlay_hint.lua:320: in function <...CVKwkT/usr/share/nvim/runtime/lua/vim/lsp/inlay_hint.lua:311>

Steps to reproduce

• Create a small rust project. For example:
  • File 'Cargo.toml' with the following content:

    [package]
    name = "inlay-hint-repro"
    version = "0.1.0"

  • File 'hello-world.rs' with the following content:

    fn main() {
        println!("Hello, world!");
    }

• Make sure rust-analyzer is installed.
• Create a 'init.lua' with the following setup:

  vim.api.nvim_create_autocmd('FileType', {
    pattern = 'rust',
    callback = function()
      vim.lsp.start({
        name = 'rust-analyzer',
        cmd = 'rust-analyzer', -- Use custom path to 'rust-analyzer' executable
        root_dir = '.',
      })
    end,
  })
  
  vim.api.nvim_create_autocmd('LspAttach', {
    callback = function(args)
      -- Wait for LSP server to start (just to be sure)
      vim.defer_fn(function() vim.lsp.inlay_hint.enable(args.bufnr, true) end, 1000)
    end,
  })

• Execute nvim --clean -u <path/to/init.lua> from the root of sample rust project.
• :split
• :call win_execute(1000, 'edit hello-world.rs') and wait for one second.

Expected behavior

Inlay hints can be automatically started even if target buffer is not current (is not in current window).

Neovim version (nvim -v)

NVIM v0.10.0-dev-2457+ga4b444252

Vim (not Nvim) behaves the same?

No (doesn't have this functionality)

Operating system/version

EndeavourOS Linux x86_64 (6.7.6-arch1-1)

Terminal name/version

st-0.9

$TERM environment variable

st-256color

Installation

appimage

[clason]

Tangent: There is the same error -- from the decoration provider! -- if you do vim.lsp.inlay_hint.enable() in a buffer without an LSP server. This case should be gracefully handled much earlier with a warning (similar to hover()) instead.