[syslinux] syslinux 6.03 bug related to rev shadow and scroll bar with vshift

[Emilio Lazo Zaia]

Hi Gene:

On 09/12/15 22:16, Gene Cumm wrote:
> On Wed, Dec 9, 2015 at 1:07 PM, Emilio Lazo Zaia via Syslinux
> <syslinux en zytor.com> wrote:
>> I thought I've found three bugs on syslinux 6.03:
> Just to be clear, is this only affecting vesamenu.c32?
You mean cmenu.c32? I didn't test it with cmenu; only vesamenu.c32 and 
menu.c32.

>
>> (1) With sample config file as is, i.e. leaving commented MENU VSHIFT and
>> MENU COLOR UNSEL but uncommented MENU COLOR SEL:
>>
>> A black "border" is displayed below the selected line and on its right edge.
> I'm not sure this is a bug but an intended effect since you're not
> touching the shadowing.  Try none.
No undesired lines with "none"... But see below.
>
>> (2) Uncommenting MENU COLOR UNSEL:
>>
>> This effect appears also on separators and on right edge on every unselected
>> lines.
I forgot to mention that when uncommenting MENU COLOR UNSEL, the 
selected line behaves correctly, although is true the paragraph above 
about unselected items and separators
> Same.
No lines with "none" on both SEL and UNSEL, but also no shadows on 
unselected items...

If we leave "rev" on UNSEL and "none" on SEL the undesired line 
reappears on selected item being the behavior the following: a black 
line above the selected item, a black line above the menu separators and 
a black line on the right edge on unselected lines. So the screen is messy.

If we specify a background image, a little distortion is apparent when 
changing between items.

>
>> (3) Uncommenting MENU VSHIFT line, unrelated to previous behavior:
>>
>> The scroll bar is not shown correctly... It behaves the same as if no VSHIFT
>> were specified, so it is "hidden" on the first page because the menu has
>> vertical shift, and the second page shows only two scroll characters but on
>> first lines instead of at bottom of the menu.
> This one feels like a bug in calculating the top location to place the
> scrollbar.  When you hit the bottom of the list, regardless of if you
> set MENU VSHIFT, it ends at the exact same position.  Fiddling with
> all of the variables, it doesn't seem like it can be fixed/worked
> around.
Exactly. It is also present with menu.c32.
>
>> syslinux.cfg file:
>>
>> PATH /boot/syslinux/modules/bios
>> UI vesamenu.c32
>> # MENU VSHIFT 10
>> MENU COLOR SEL          * #FFFFD600 #00000000 *
>> # MENU COLOR UNSEL        * #FFFFFFFF #00000000 rev
>>
>> LABEL XXXXX
>> MENU LABEL XXXXX
>> COM32 chain.c32
>> APPEND XXXX
>>
>> LABEL XXXXX
>> MENU LABEL XXXXX
>> COM32 chain.c32
>> APPEND XXXX
> For any other situation, repeating LABELs would be an absolutely
> horrible idea and even here I'd suggest against it.  Here's a better
> idea:
Of course, thank you... I've modified my syslinux.cfg to post a minimum 
working example without taking into account the repeating labels.

Emilio