refactor(treesitter): always return valid range from parse() #32273

Problem:
When running an initial parse, parse() returns an empty table rather
than an actual range. In `languagetree.lua`, we manually check if
a parse was incremental to determine the changed parse region.

Solution:
- Always return a range (in the C side) from parse().
- Simplify the language tree code a bit.
- Logger no longer shows empty ranges on the initial parse.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/nvim/lua/treesitter.c b/src/nvim/lua/treesitter.c
index c7999ac077..3e33fcd142 100644
--- a/src/nvim/lua/treesitter.c
+++ b/src/nvim/lua/treesitter.c
@@ -500,7 +500,8 @@ static int parser_parse(lua_State *L)
   // The new tree will be pushed to the stack, without copy, ownership is now to the lua GC.
   // Old tree is owned by lua GC since before
   uint32_t n_ranges = 0;
-  TSRange *changed = old_tree ? ts_tree_get_changed_ranges(old_tree, new_tree, &n_ranges) : NULL;
+  TSRange *changed = old_tree ? ts_tree_get_changed_ranges(old_tree, new_tree, &n_ranges)
+                              : ts_tree_included_ranges(new_tree, &n_ranges);
 
   push_tree(L, new_tree);  // [tree]