bug#51550: 29.0.50; Customize Group INS buttons sometimes don't have a left box line

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

>> Yes, widget-field has a box on master, while it doesn't on emacs-28.

> The other way around, I guess?

Causing widget-field to have a box (which gets extended to the end of
the line) makes the custom button on the next line lose its start box
line, so it's not the other way around.

> Which buggy code was that, and where did I suggest disabling it?

The code that added a box to widget-field.  But it seems that Stefan
suggested to disable it, and you only happened to concur.

Maybe this will help jog your memory (but you really ought to look at
the whole bug report.)

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Kangas <stefan@marxist.se>
>> Date: Wed, 3 Nov 2021 00:03:00 -0700
>> Cc: stephen.berman@gmx.net, 51550@debbugs.gnu.org
>> 
>> It seems like the entire line is shifted a pixel to the left when using
>> :box, but only on the second consecutive line.  I tried experimenting
>> with :box 1, :box -1, and I get the same result.
>> 
>> Are we sure that's not a bug in the display code?
>
> I don't know, the arrangement of faces on that button is complicated,
> to say the least.  I don't think I even understand which parts of the
> display is the widget-field face applied to.  Can you show the
> complete definition of the button face at the first line and the
> non-first line?
>
>> In any case, we could revert the commit for emacs-28 and continue 
>> investigating
>> on master.
>
> Yes, I think we should do that.

Thanks.