Co-authored-by: Dustin S. <dstackmasta27@gmail.com>
Co-authored-by: Ferenc Fejes <fejes@inf.elte.hu>
Co-authored-by: Maria José Solano <majosolano99@gmail.com>
Co-authored-by: Yochem van Rosmalen <git@yochem.nl>
Co-authored-by: brianhuster <phambinhanctb2004@gmail.com>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>

Problem: setting `loclist = true` makes `on_list` being ignored. This
  was not a problem before, but with `vim.lsp.buf.document_symbol` using
  `loclist = true` as default it is needed to explicitly pass `loclist =
  false` in order to use custom `on_list`.

Solution: prefer `on_list` over `loclist` and document the latter as
  taking effect only in the default handler.

Problem:

    vim.lsp.completion.enable(true, client.id, bufnr)
    vim.lsp.completion.enable(false, client.id, bufnr)

    Error detected while processing LspDetach Autocommands for "*":
    Error executing lua callback: …/lsp/completion.lua:701: Vim:E367: No such group: "vim/lsp/completion-22"
    stack traceback:
            [C]: in function 'nvim_del_augroup_by_name'
            …/lsp/completion.lua:701: in function 'disable_completions'
            …/lsp/completion.lua:724: in function 'enable'

Solution:
Delete the correct augroup.

Problem:
The filetype for the floating window buffer is being set before its context is fully initialized.
This results in `FileType` events not receiving the correct context.

Solution:
Set the filetype after the floating preview window and its buffer variables are
fully configured to ensure proper context is provided.

Follow up to https://github.com/neovim/neovim/pull/32072

If there is no prefix (e.g. at the start of word boundary or a line), it
always used the `filterText` because the `match` function always
returned false.

Problem: Not able to open document symbols for different buffers

Solution: Use the location list as default.

To switch back to previous behavior (qflist):

  vim.lsp.buf.document_symbol({ loclist = false })

Fixes: #31832

Problem:

With language servers like lemminx, completing xml tags like `<mo` first
shows the right candidates (`modules`) but after typing `d` the
candidates disappear.

This is because the server returns:

    [...]
    filterText = "<module",
    label = "module",
    textEdit = {
      newText = "<module>$1</module>$0",

Which resulted in `module` being used as `word`, and `module` doesn't
match the prefix `<mo`. Typing `d` causes the `complete()` filtering
mechanism to kick in and remove the entry.

Solution:

Use `<module` from the `filterText` as `word` if the textEdit/label
heuristic doesn't match.

Ref https://github.com/neovim/neovim/discussions/32015