Re: [PATCH] normal: fix get_logical_num_lines

[Andrei Borzenkov]

On Wed, Dec 23, 2015 at 7:45 AM, Michael Chang <address@hidden> wrote:
> In menu editing mode, grub2 shows bogus line if the character being
> edited is at last column of entry. This patch fixes the problem by
> having the get_logical_num_lines function to calculate correct number of
> lines.
>
> ---
>  grub-core/normal/menu_entry.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/grub-core/normal/menu_entry.c b/grub-core/normal/menu_entry.c
> index 62c7e16..1d4b0c6 100644
> --- a/grub-core/normal/menu_entry.c
> +++ b/grub-core/normal/menu_entry.c
> @@ -128,7 +128,7 @@ get_logical_num_lines (struct line *linep, struct 
> per_term_screen *term_screen)
>  {
>    return (grub_getstringwidth (linep->buf, linep->buf + linep->len,
>                                term_screen->term)
> -         / (unsigned) term_screen->geo.entry_width) + 1;
> +         / ((unsigned) term_screen->geo.entry_width + 1)) + 1;

No, that's wrong. Consider entry_width = 10 and grub_getstringwidth =
21. It needs 3 lines but your change gives only 2.

It sounds like we need

string_width = grub_getstringwidth (linep->buf, linep->buf +
linep->len, term_screen->term);
if (!string_width)
  return 1;
return (string_width + (unsigned) term_screen->geo.entry_width - 1) /
(unsigned) term_screen->geo.entry_width;

Could you test if it works for you?