Syslinux - Apr 2019 - Fix: menu immediate for submenu

Hello,

the hot key assigned to a MENU BEGIN (via MENU LABEL) doesn't cause the
submenu to be entered automatically when MENU IMMEDIATE is used (at previous
level). Here's a patch over syslinux 6.03. Patch was tested on Debian.

Regards
Dany

*Sample config*
# hot keys: S,1,2 are immediate (screen flash), but not E
MENU IMMEDIATE
LABEL standard
 MENU LABEL ^Standard

MENU BEGIN
 MENU LABEL ^Extra
 LABEL extra1
   MENU LABEL ^1. One
 LABEL extra2
   MENU LABEL ^2. Two
MENU END
# end-of-config

*Code analysis*
The 'menu_entry' associated with a label inherits the
'immediate' flag of the parent 'menu' [record()] unless
overridden for the label. The sub 'menu' inherits the
'immediate' flag of the parent 'menu' [new_menu()]. But the
'menu_entry' associated with a sub-menu doesn't inherit the
'immediate' flag.

Not sure if this was an oversight in the original delivery of the feature, or if
it was intentional (the patch description does cover the design intention)

*Possible issue*
There is no way to individually set MENU IMMEDIATE or MENU NOIMMEDIATE for the
submenu entries (existing limitation). If someone want to revert to the broken
behaviour, the main setting has to be MENU NOIMMEDIATE, and each label must be
individually marked with MENU IMMEDIATE.

*Patch*
--- syslinux-6.03.orig/com32/menu/readconfig.c  2019-04-16 07:42:25.281964266
-0500
+++ syslinux-6.03/com32/menu/readconfig.c       2019-04-16 07:43:06.332309963
-0500
@@ -437,6 +437,7 @@ static struct menu *begin_submenu(const
 
     me = new_entry(current_menu);
     me->displayname = refstrdup(tag);
+    me->immediate = current_menu->immediate;
     return new_menu(current_menu, me, refstr_get(me->displayname));
 }
 
# end-of-patch

> Hello,
> 
> the hot key assigned to a MENU BEGIN (via MENU LABEL) doesn't cause the
> submenu to be entered automatically when MENU IMMEDIATE is used (at
previous
> level). Here's a patch over syslinux 6.03. Patch was tested on Debian.
> 
> Regards
> Dany
> 
> *Sample config*
> # hot keys: S,1,2 are immediate (screen flash), but not E
> MENU IMMEDIATE
> LABEL standard
>  MENU LABEL ^Standard
> 
> MENU BEGIN
>  MENU LABEL ^Extra
>  LABEL extra1
>    MENU LABEL ^1. One
>  LABEL extra2
>    MENU LABEL ^2. Two
> MENU END
> # end-of-config
 
 
Thank you for the patch. Hopefully the developers will at least ACK it.

Have you tested (before and after the patch) what happens when the optional 
"tagname" is actually used for MENU BEGIN?

I mean, instead of just:

MENU BEGIN
 MENU LABEL ^Extra

what happens (before and after the patch) when you use:

MENU BEGIN Extra
 MENU LABEL ^Extra


Reminder: The tagname (i.e. the first "Extra" in the same row as
"MENU BEGIN"
in my example above) acts as a label for MENU BEGIN.


Also, what happens (before and after the patch) if there is a LABEL directive 
right before MENU BEGIN?

I mean, what happens if the cfg is:

LABEL Extra
MENU BEGIN
 MENU LABEL ^Extra

(I admit it has been years since I last tested MENU BEGIN with all these 
combinations, so I don't exactly remember whether using a LABEL right before
MENU BEGIN is actually valid/acceptable.)

Again, thank you for the suggested patch.

Thank you and Best Regards,
Ady.