3 files changed, 21 insertions, 7 deletions
diff --git a/runtime/lua/vim/treesitter/highlighter.lua b/runtime/lua/vim/treesitter/highlighter.lua
index e99994c8a9..d77a0d0d03 100644
--- a/runtime/lua/vim/treesitter/highlighter.lua
+++ b/runtime/lua/vim/treesitter/highlighter.lua
@@ -88,7 +88,6 @@ function TSHighlighter.new(tree, opts)
     end
   end
 
-  self.orig_syntax = vim.bo[self.bufnr].syntax
   self.orig_spelloptions = vim.bo[self.bufnr].spelloptions
 
   vim.bo[self.bufnr].syntax = ''
@@ -120,8 +119,11 @@ function TSHighlighter:destroy()
   end
 
   if vim.api.nvim_buf_is_loaded(self.bufnr) then
-    vim.bo[self.bufnr].syntax = self.orig_syntax
     vim.bo[self.bufnr].spelloptions = self.orig_spelloptions
+    vim.b[self.bufnr].ts_highlight = nil
+    if vim.g.syntax_on == 1 then
+      a.nvim_exec_autocmds('FileType', { group = 'syntaxset', buffer = self.bufnr })
+    end
   end
 end
 
diff --git a/runtime/lua/vim/treesitter/language.lua b/runtime/lua/vim/treesitter/language.lua
index c92d63b8c4..8634e53b7b 100644
--- a/runtime/lua/vim/treesitter/language.lua
+++ b/runtime/lua/vim/treesitter/language.lua
@@ -6,7 +6,7 @@ local M = {}
 ---
 --- Parsers are searched in the `parser` runtime directory, or the provided {path}
 ---
----@param lang string Language the parser should parse
+---@param lang string Language the parser should parse (alphanumerical and `_` only)
 ---@param path (string|nil) Optional path the parser is located at
 ---@param silent (boolean|nil) Don't throw an error if language not found
 ---@param symbol_name (string|nil) Internal symbol name for the language to load
@@ -16,13 +16,19 @@ function M.require_language(lang, path, silent, symbol_name)
     return true
   end
   if path == nil then
-    local fname = 'parser/' .. vim.fn.fnameescape(lang) .. '.*'
+    if not (lang and lang:match('[%w_]+') == lang) then
+      if silent then
+        return false
+      end
+      error("'" .. lang .. "' is not a valid language name")
+    end
+
+    local fname = 'parser/' .. lang .. '.*'
     local paths = a.nvim_get_runtime_file(fname, false)
     if #paths == 0 then
       if silent then
         return false
       end
-
       error("no parser for '" .. lang .. "' language, see :help treesitter-parsers")
     end
     path = paths[1]
diff --git a/runtime/lua/vim/treesitter/query.lua b/runtime/lua/vim/treesitter/query.lua
index 4bec5db527..dbf134573d 100644
--- a/runtime/lua/vim/treesitter/query.lua
+++ b/runtime/lua/vim/treesitter/query.lua
@@ -419,7 +419,8 @@ local directive_handlers = {
 --- Adds a new predicate to be used in queries
 ---
 ---@param name string Name of the predicate, without leading #
----@param handler function(match:string, pattern:string, bufnr:number, predicate:function)
+---@param handler function(match:table, pattern:string, bufnr:number, predicate:string[])
+---   - see |vim.treesitter.query.add_directive()| for argument meanings
 function M.add_predicate(name, handler, force)
   if predicate_handlers[name] and not force then
     error(string.format('Overriding %s', name))
@@ -436,7 +437,12 @@ end
 --- metadata table `metadata[capture_id].key = value`
 ---
 ---@param name string Name of the directive, without leading #
----@param handler function(match:string, pattern:string, bufnr:number, predicate:function, metadata:table)
+---@param handler function(match:table, pattern:string, bufnr:number, predicate:string[], metadata:table)
+---   - match: see |treesitter-query|
+---      - node-level data are accessible via `match[capture_id]`
+---   - pattern: see |treesitter-query|
+---   - predicate: list of strings containing the full directive being called, e.g.
+---     `(node (#set! conceal "-"))` would get the predicate `{ "#set!", "conceal", "-" }`
 function M.add_directive(name, handler, force)
   if directive_handlers[name] and not force then
     error(string.format('Overriding %s', name))