nvim: Fix ltex disabled autostart

Fixes #1ef7570.

We implement our own autostart-aware lsp register function. Any lsp
which has the option {autostart=false} set at their config root will be
not automatically enabled and can instead be enabled on demand.

nvim/.config/nvim/lua/plugins/lsp.lua

@@ -56,9 +56,14 @@ local lsp = {
 			vim.fn.sign_define("DiagnosticSignInfo", { text = "", texthl = "DiagnosticSignInfo" })
 			vim.fn.sign_define("DiagnosticSignHint", { text = "", texthl = "DiagnosticSignHint" })
 
-			local function register(server_name, config)
+			local function register(server_name, config, enabled)
 				if vim.fn.has("nvim-0.11") == 1 then
 					vim.lsp.config(server_name, config)
+					if enabled == false or vim.lsp.config[server_name]["autostart"] == false then
+						vim.lsp.enable(server_name, false)
+					else
+						vim.lsp.enable(server_name, true)
+					end
 				else
 					require("lspconfig")[server_name].setup(config)
 				end
@@ -186,19 +191,28 @@ local lsp = {
 			vim.api.nvim_create_autocmd("User", {
 				pattern = "SpellEnable",
 				callback = function()
-					register("ltex", {
-						on_attach = function(_, _)
-							if require("core.util").is_available("ltex_extra") then
-								require("ltex_extra").setup()
-							end
-						end,
-						settings = {
-							ltex = {
-								language = vim.o.spelllang,
-							},
-						},
+					local mapped = {}
+					local lang_map = {
+						en_us = "en-US",
+						en_gb = "en-GB",
+						de_de = "de-DE",
+					}
+					for _, v in ipairs(vim.opt.spelllang:get()) do
+						table.insert(mapped, lang_map[v])
+					end
+					vim.lsp.config("ltex", {
+						settings = { ltex = { language = mapped } },
 					})
-					vim.cmd("LspStart ltex")
+					-- single-shot setup: Enable for this buffer
+					-- but instantly disable again globally
+					vim.lsp.enable("ltex")
+					vim.lsp.enable("ltex", false)
+				end,
+			})
+			vim.api.nvim_create_autocmd("User", {
+				pattern = "SpellDisable",
+				callback = function()
+					vim.lsp.enable("ltex", false)
 				end,
 			})
 		end,