Fix an issue when searching subtree backward (bug#67117)

* src/treesit.c (treesit_traverse_child_helper):
Do not call treesit_traverse_sibling_helper when the named node is
required and the last child is the named node.
Otherwise treesit_traverse_sibling_helper will move cursor to the
previous sibling and last node will be skipped.
* test/src/treesit-tests.el (treesit-search-subtree-forward-1):
(treesit-search-subtree-backward-1):
Add tests.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/treesit.c b/src/treesit.c
index 45de82ec096..04ea8958b96 100644
--- a/src/treesit.c
+++ b/src/treesit.c
@@ -3061,9 +3061,9 @@ treesit_traverse_child_helper (TSTreeCursor *cursor,
       /* First go to the last child.  */
       while (ts_tree_cursor_goto_next_sibling (cursor));
 
-      if (!named)
+      if (!named || (named && ts_node_is_named (ts_tree_cursor_current_node(cursor))))
         return true;
-      /* Else named... */
+      /* Else named is required and last child is not named node */
       if (treesit_traverse_sibling_helper(cursor, false, true))
         return true;
       else