fix(treesitter): properly restore `'syntax'` (#21358)

2 files changed, 4 insertions, 6 deletions

diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index 7813c2edb2..25f0e7dc5e 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -327,12 +327,8 @@ end
 ---@param lang (string|nil) Language of the parser (default: buffer filetype)
 function M.start(bufnr, lang)
   bufnr = bufnr or a.nvim_get_current_buf()
-
   local parser = M.get_parser(bufnr, lang)
-
   M.highlighter.new(parser)
-
-  vim.b[bufnr].ts_highlight = true
 end
 
 --- Stops treesitter highlighting for a buffer
@@ -344,8 +340,6 @@ function M.stop(bufnr)
   if M.highlighter.active[bufnr] then
     M.highlighter.active[bufnr]:destroy()
   end
-
-  vim.bo[bufnr].syntax = 'on'
 end
 
 --- Open a window that displays a textual representation of the nodes in the language tree.
diff --git a/runtime/lua/vim/treesitter/highlighter.lua b/runtime/lua/vim/treesitter/highlighter.lua
index f5e5ca1988..99aedf60c5 100644
--- a/runtime/lua/vim/treesitter/highlighter.lua
+++ b/runtime/lua/vim/treesitter/highlighter.lua
@@ -88,7 +88,9 @@ function TSHighlighter.new(tree, opts)
     end
   end
 
+  self.orig_syntax = vim.bo[self.bufnr].syntax
   vim.bo[self.bufnr].syntax = ''
+  vim.b[self.bufnr].ts_highlight = true
 
   TSHighlighter.active[self.bufnr] = self
 
@@ -114,6 +116,8 @@ function TSHighlighter:destroy()
   if TSHighlighter.active[self.bufnr] then
     TSHighlighter.active[self.bufnr] = nil
   end
+
+  vim.bo[self.bufnr].syntax = self.orig_syntax
 end
 
 ---@private