bug: flash.treesitter preselects "a" label even if the user has defined custom labels

[IndianBoy42]

Did you check docs and existing issues?

• I have read all the flash.nvim docs
• I have searched the existing issues of flash.nvim
• I have searched the existing issues of plugins related to this issue

Neovim version (nvim -v)

NVIM v0.10.0-dev-541+g96b94f8d7

Operating system/version

Pop!_OS 22.04 LTS

Describe the bug

This line basically assumes that a is the first label:

https://github.com/folke/flash.nvim/blob/455ba61cd0e48b9e3a28e9e1fa1a3364d57e7538/lua/flash/plugins/treesitter.lua#LL66C30-L66C31

Steps To Reproduce

1. config.modes.treesitter.labels = "fdsajkl"
2. vS and see the labels and selection

Expected Behavior

The inner most treesitter node should be preselected (now labelled by f). Instead the node labelled a is selected.

Repro

-- DO NOT change the paths and don't remove the colorscheme
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.loop.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 = {
	"folke/tokyonight.nvim",
	{
		"folke/flash.nvim",
		opts = {
			modes = {
				treesitter = { labels = "zayx" },
			},
		},
		keys = {
			{
				"S",
				mode = { "o", "x" },
				function()
					require("flash").treesitter()
				end,
			},
		},
	},
	-- add any other plugins here
}
require("lazy").setup(plugins, {
	root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")
-- add anything else here

[folke]

Good catch!