Syslinux - Sep 2012 - Final line of menu selectable even if it is disabled

I have a menu conf as follows:

LABEL enabled, use as item
LABEL disabled, use as description
SEPARATOR
LABEL enabled, use as item
LABEL disabled, use as description

In this situation, I expect the cursors to be able to select from only the two
enabled lines.

However, the final disabled line is also selectable. 

Even if I put a final separator and/or disabled label the final line of the menu
is still selectable.

Full conf: http://pastebin.com/U6zQVbt6

So there seems to be an edge case scenario that means the final line of a menu
is selectable when it should not be.

Any thoughts?

matt

> From: matt.sephton at gmail.com
> Date: Wed, 5 Sep 2012 10:53:41 +0100
> To: Syslinux at zytor.com
> Subject: [syslinux] Final line of menu selectable even if it is disabled
> 
> I have a menu conf as follows:
> 
> LABEL enabled, use as item
> LABEL disabled, use as description
> SEPARATOR
> LABEL enabled, use as item
> LABEL disabled, use as description
> 
> In this situation, I expect the cursors to be able to select from only the
two enabled lines.
> 
> However, the final disabled line is also selectable. 
> 
> Even if I put a final separator and/or disabled label the final line of the
menu is still selectable.
> 
> Full conf: http://pastebin.com/U6zQVbt6
> 
> So there seems to be an edge case scenario that means the final line of a
menu is selectable when it should not be.
> 
> Any thoughts?
> 
 
 It was already noted by someone else before
 ( see http://www.syslinux.org/archives/2012-April/017463.html ) but I
 don't know if something was done about it.
 To be accurate, the specific "disabled" menu entry is
"selectable" (while
 it shouldn't), but other than that, you can't do anything with it;
 you can't actually take any action, other than to select a different
 entry. In other words, while that last "disabled" menu entry is
"selected",
 keys like "tab" and "enter" are not going to do anything.
  
 Yet, strictly speaking, that menu entry shouldn?t be "selectable".

On 6 Sep 2012, at 21:53, Gene Cumm <gene.cumm at gmail.com> wrote:
> On Sep 6, 2012 9:14 AM, "Matt Sephton" <matt.sephton at
gmail.com> wrote:
> 
>> Let me know if there is an official bug tracker and I will report it
there
> 
> At the moment, this is as close to a bug tracker as you get.
OK, thanks :)

On Sep 5, 2012 6:50 AM, "Matt Sephton" <matt.sephton at
gmail.com> wrote:
>
> I have a menu conf as follows:
>
> LABEL enabled, use as item
> LABEL disabled, use as description
> SEPARATOR
> LABEL enabled, use as item
> LABEL disabled, use as description
>
> In this situation, I expect the cursors to be able to select from only
the two enabled lines.
>
> However, the final disabled line is also selectable.
>
> Even if I put a final separator and/or disabled label the final line of
the menu is still selectable.
>
> Full conf: http://pastebin.com/U6zQVbt6
>
> So there seems to be an edge case scenario that means the final line of a
menu is selectable when it should not be.
>
> Any thoughts?
>
> matt
I presume that when you add one more LABEL at the end, the LABEL that's
currently at the end is no longer selectable?

--Gene

On Wed, 2012-09-05 at 10:53 +0100, Matt Sephton wrote:
> I have a menu conf as follows:
> 
> LABEL enabled, use as item
> LABEL disabled, use as description
> SEPARATOR
> LABEL enabled, use as item
> LABEL disabled, use as description
> 
> In this situation, I expect the cursors to be able to select from only the
two enabled lines.
> 
> However, the final disabled line is also selectable. 
> 
> Even if I put a final separator and/or disabled label the final line of the
menu is still selectable.
> 
> Full conf: http://pastebin.com/U6zQVbt6
> 
> So there seems to be an edge case scenario that means the final line of a
menu is selectable when it should not be.
> 
> Any thoughts?
Matt, it does indeed look like you're hitting an edge case.

Could you apply the following patch on top of 4.06-pre12 and see whether
your issue is resolved?

diff --git a/com32/menu/menumain.c b/com32/menu/menumain.c
index 5b3f6bd..7c58979 100644
--- a/com32/menu/menumain.c
+++ b/com32/menu/menumain.c
@@ -958,8 +958,7 @@ static const char *run_menu(void)
 
 	case KEY_DOWN:
 	case KEY_CTRL('N'):
-	    while (entry < cm->nentries - 1) {
-		entry++;
+	    while (++entry < cm->nentries) {
 		if (entry >= top + MENU_ROWS)
 		    top += MENU_ROWS;
 		if (!is_disabled(cm->menu_entries[entry]))


-- 
Matt Fleming, Intel Open Source Technology Center