Bug: Telescope lsp_document_symbols errors out

[dpetka2001]

Description

When you do :lua require("telescope.builtin").lsp_document_symbols({symbols = {"Class"}}) in a file that has no such symbols then you get error

[telescope.filter_symbols]: class symbol(s) were not part of the query results                                              
Error executing vim.schedule lua callback: vim/shared.lua:0: t: expected table, got nil                                     
stack traceback:                                                                                                            
        [C]: in function 'error'                                                                                            
        vim/shared.lua: in function 'validate'                                                                              
        vim/shared.lua: in function 'tbl_isempty'                                                                           
        ...o/plugins/telescope.nvim/lua/telescope/builtin/__lsp.lua:364: in function 'handler'                              
        ...re/bob/nightly/share/nvim/runtime/lua/vim/lsp/client.lua:669: in function ''                                     
        vim/_editor.lua: in function <vim/_editor.lua:0>         

That means that we get up to this point in this function, thus we get the warning and then the error. Since, the function doesn't explicitly return anything after these 2 warnings happen, it should implicitly return nil, thus the error we get.

Returning an empty table between lines 182-183 return {} or changing this line to locations = utils.filter_symbols(locations, opts, symbols_sorter) or {} seems to solve the error.

Not familiar with Telescope codebase overall and fairly new to programming, so I'm not sure which the best implementation is and if what I proposed in the previous paragraph might result to some other side-effects, so I'll just leave it up to you how to best solve this situation.

Neovim version

NVIM v0.11.0-dev-1295+gbf5c1346c5
Build type: RelWithDebInfo
LuaJIT 2.1.1732813678

Operating system and version

Linux Mint 21.3

Telescope version / branch / rev

commit 2eca9ba

checkhealth telescope

telescope:                                              health#telescope#check

Checking for required plugins ~
- OK plenary installed.
- OK nvim-treesitter installed.

Checking external dependencies ~
- OK rg: found ripgrep 14.1.1 (rev 4649aa9700)
- OK fd: found fd 10.2.0

===== Installed extensions ===== ~

Steps to reproduce

Run the minimal config with nvim -u minimal.lua and after you open a file (I opened minimal.lua myself) and did :lua require("telescope.builtin").lsp_document_symbols({symbols = {"Class"}}) and I got the error I described.

Expected behavior

Should not error.

Actual behavior

Errors with

Error executing vim.schedule lua callback: vim/shared.lua:0: t: expected table, got nil                                     
stack traceback:                                                                                                            
        [C]: in function 'error'                                                                                            
        vim/shared.lua: in function 'validate'                                                                              
        vim/shared.lua: in function 'tbl_isempty'                                                                           
        ...o/plugins/telescope.nvim/lua/telescope/builtin/__lsp.lua:364: in function 'handler'                              
        ...re/bob/nightly/share/nvim/runtime/lua/vim/lsp/client.lua:669: in function ''                                     
        vim/_editor.lua: in function <vim/_editor.lua:0>         

Minimal config

local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "cache" }) do
	vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end

-- bootstrap lazy
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.uv.fs_stat(lazypath) then
	vim.fn.system({
		"git",
		"clone",
		"--filter=blob:none",
		"https://github.com/folke/lazy.nvim.git",
		lazypath,
	})
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
	{
		"neovim/nvim-lspconfig",
	},
	{
		"williamboman/mason.nvim",
		opts = {},
	},
	{
		"williamboman/mason-lspconfig.nvim",
		opts = {
			ensure_installed = {
				"lua_ls",
			},
		},
	},
	{
		"nvim-treesitter/nvim-treesitter",
		opts = {
			ensure_installed = { "lua" },
		},
		config = function(_, opts)
			require("nvim-treesitter.configs").setup(opts)
		end,
	},
	{
		"nvim-telescope/telescope.nvim",
		dependencies = {
			"nvim-lua/plenary.nvim",
		},
		config = function()
			-- ADD INIT.LUA SETTINGS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
			require("telescope").setup({})
		end,
	},
}

require("lazy").setup(plugins, {
	root = root .. "/plugins",
})
require("lspconfig").lua_ls.setup {}