Re: master a5eb9f6ad4e 2/3: Catch signals produced by PRED in tree-sitter search functions

[Po Lu <luangruo@yahoo.com>]

Yuan Fu <casouri@gmail.com> writes:

> +/** Cleanup function for cursor.  */
> +static void treesit_traverse_cleanup_cursor(void *cursor)
> +{
> +  ts_tree_cursor_delete ((TSTreeCursor *) cursor);
> +}

Please fix your coding style: place a newline after `void', and a space
after `treesit_traverse_cleanup_cursor'.

>  DEFUN ("treesit-search-subtree",
>         Ftreesit_search_subtree,
>         Streesit_search_subtree, 2, 5, 0,
> @@ -3288,12 +3294,18 @@ Return the first matched node, or nil if none matches.  */)
>    if (!treesit_cursor_helper (&cursor, XTS_NODE (node)->node, parser))
>      return return_value;
>  
> +  specpdl_ref count = SPECPDL_INDEX ();
> +  record_unwind_protect_ptr (treesit_traverse_cleanup_cursor, &cursor);
> +
>    if (treesit_search_dfs (&cursor, predicate, parser, NILP (backward),
>  			  NILP (all), the_limit, false))
>      {
>        TSNode node = ts_tree_cursor_current_node (&cursor);
>        return_value = make_treesit_node (parser, node);
>      }
> +
> +  unbind_to (count, Qnil);
> +
>    ts_tree_cursor_delete (&cursor);
>    return return_value;
>  }
> @@ -3345,12 +3357,18 @@ always traverse leaf nodes first, then upwards.  */)
>    if (!treesit_cursor_helper (&cursor, XTS_NODE (start)->node, parser))
>      return return_value;
>  
> +  specpdl_ref count = SPECPDL_INDEX ();
> +  record_unwind_protect_ptr (treesit_traverse_cleanup_cursor, &cursor);
> +
>    if (treesit_search_forward (&cursor, predicate, parser,
>  			      NILP (backward), NILP (all)))
>      {
>        TSNode node = ts_tree_cursor_current_node (&cursor);
>        return_value = make_treesit_node (parser, node);
>      }
> +
> +  unbind_to (count, Qnil);
> +
>    ts_tree_cursor_delete (&cursor);
>    return return_value;
>  }
> @@ -3467,8 +3485,14 @@ a regexp.  */)
>       to use treesit_cursor_helper.  */
>    TSTreeCursor cursor = ts_tree_cursor_new (XTS_NODE (root)->node);
>  
> +  specpdl_ref count = SPECPDL_INDEX ();
> +  record_unwind_protect_ptr (treesit_traverse_cleanup_cursor, &cursor);
> +
>    treesit_build_sparse_tree (&cursor, parent, predicate, process_fn,
>  			     the_limit, parser);
> +
> +  unbind_to (count, Qnil);
> +
>    ts_tree_cursor_delete (&cursor);
>    Fsetcdr (parent, Fnreverse (Fcdr (parent)));
>    if (NILP (Fcdr (parent)))

Unless you remove the redundant call to `ts_tree_cursor_delete' after
`unbind_to', you get a double free.