[syslinux] Fix: hotkey uppercasing too wide

[Dany St-Amant]

Hello,

 It appears that my patch breaks the highlighting of the hot key, when the hot key is not a letter. I will provide an updated version next week.

> Le 17 avr. 2019 à 15:35, Dany St-Amant <dany.ephemeral.2014 at icloud.com> a écrit :
> 
> Hello,
> 
> Stumble upon this issue. If one define digits as hotkeys, the action is also taken for the non-reserved CTRL-P to CTRL-Y (also affect ASCII prior to digits). Here's a quick patch, quickly tested for action on uppercase/lowercase and digit and inaction on "matching" CTRL key.
> 
> Regards,
> Dany
> 
> *Sample config section*
> LABEL extra2
>  MENU LABEL ^2. Two
>  # pressing 2 activates this entry
>  # pressing CTRL-R activates this entry (prior to fix below)
> LABEL extradollar
>  MENU LABEL ^$. Dollar
>  # pressing $ activates this entry
>  # pressing CTRL-D activates this entry (prior to fix below)
> 
> *Patch*
> # Sorry for the crypto one-liners
> --- syslinux-6.03/com32/menu/menumain.c.orig    2014-10-06 11:27:44.000000000 -0500
> +++ syslinux-6.03/com32/menu/menumain.c    2019-04-17 12:11:41.677824723 -0500
> @@ -1081,7 +1081,7 @@ static const char *run_menu(void)
>        break;
>    default:
>        if (key > 0 && key < 0xFF) {
> -        key &= ~0x20;    /* Upper case */
> +        key &= ((key & 0xE0) == 0x60 ? ~0x20 : 0xFF);    /* Upper case */
>        if (cm->menu_hotkeys[key]) {
>            key_timeout = 0;
>            entry = cm->menu_hotkeys[key]->entry;
> --- syslinux-6.03/com32/menu/readconfig.c.orig    2019-04-17 11:53:15.794263379 -0500
> +++ syslinux-6.03/com32/menu/readconfig.c    2019-04-17 12:13:43.549878848 -0500
> @@ -279,7 +279,7 @@ static void consider_for_hotkey(struct m
> 
>     if (me->action != MA_DISABLED) {
>    if (p && p[1]) {
> -        unsigned char hotkey = p[1] & ~0x20;
> +        unsigned char hotkey = p[1] & ((hotkey & 0xE0) == 0x60 ? ~0x20 : 0xFF);
>        if (!m->menu_hotkeys[hotkey]) {
>        me->hotkey = hotkey;
>        m->menu_hotkeys[hotkey] = me;
> 
> *Patch limitation*
> Six non-letters are still mapped to "uppercase":
> ' -> @
> { -> [
> | -> \
> } -> ]
> ~ -> ^
> DEL -> _
>