fix(treesitter): do not track ranges of the root tree (#22912)

Fixes #22911

runtime/lua/vim/treesitter/languagetree.lua

@@ -57,6 +57,7 @@ local Range = require('vim.treesitter._range')
 ---@field private _injection_query Query Queries defining injected languages
 ---@field private _opts table Options
 ---@field private _parser TSParser Parser for language
+---@field private _has_regions boolean
 ---@field private _regions Range6[][]?
 ---List of regions this tree should manage and parse. If nil then regions are
 ---taken from _trees. This is mostly a short-lived cache for included_regions()
@@ -440,6 +441,8 @@ end
 ---@private
 ---@param new_regions Range6[][] List of regions this tree should manage and parse.
 function LanguageTree:set_included_regions(new_regions)
+  self._has_regions = true
+
   -- Transform the tables from 4 element long to 6 element long (with byte offset)
   for _, region in ipairs(new_regions) do
     for i, range in ipairs(region) do
@@ -468,7 +471,8 @@ function LanguageTree:included_regions()
     return self._regions
   end
 
-  if #self._trees == 0 then
+  if not self._has_regions or #self._trees == 0 then
+    -- treesitter.c will default empty ranges to { -1, -1, -1, -1, -1, -1}
     return { {} }
   end
 
@@ -744,6 +748,10 @@ function LanguageTree:_edit(
 
   -- Validate regions after editing the tree
   self:_iter_regions(function(_, region)
+    if #region == 0 then
+      -- empty region, use the full source
+      return false
+    end
     for _, r in ipairs(region) do
       if Range.intercepts(r, changed_range) then
         return false

test/functional/treesitter/parser_spec.lua

@@ -948,4 +948,48 @@ int x = INT_MAX;
       [16] = '1',
       [17] = '0' }, get_fold_levels())
   end)
+
+  it('tracks the root range properly (#22911)', function()
+    insert([[
+      int main() {
+        int x = 3;
+      }]])
+
+    local query0 = [[
+      (declaration) @declaration
+      (function_definition) @function
+    ]]
+
+    exec_lua([[
+      vim.treesitter.start(0, 'c')
+    ]])
+
+    local function run_query()
+      return exec_lua([[
+      local query = vim.treesitter.query.parse("c", ...)
+      parser = vim.treesitter.get_parser()
+      tree = parser:parse()[1]
+      res = {}
+      for id, node in query:iter_captures(tree:root()) do
+        table.insert(res, {query.captures[id], node:range()})
+      end
+      return res
+      ]], query0)
+    end
+
+    eq({
+      { 'function', 0, 0, 2, 1 },
+      { 'declaration', 1, 2, 1, 12 }
+    }, run_query())
+
+    helpers.command'normal ggO'
+    insert('int a;')
+
+    eq({
+      { 'declaration', 0, 0, 0, 6 },
+      { 'function', 1, 0, 3, 1 },
+      { 'declaration', 2, 2, 2, 12 }
+    }, run_query())
+
+  end)
 end)