bug#73911: Issue with `widget-specify-button'

[Mauro Aranda <maurooaranda@gmail.com>]

David Ponce <da_vid@orange.fr> writes:

 > On 2024-12-31 12:34, Mauro Aranda wrote:
 > [...]
 >>  >> > > > Mauro, any comments?
 >>  >> > > >
 >>  >> > > >
 >>  >> > > >
 >> I don't really know the effects that this change could have (whether
 >> good or bad).  The added invisible space comes from Bug#51550, which
 >> involved some discussions about the display engine itself.
 >> I had trouble reproducing the bug itself, since I don't understand
 >> what
 >> the unexpected result is.
 >> David, I'm sorry it took me so long to reply, but can you explain a
 >> bit
 >> more what's the unexpected result? Thank you.
 >>
 >
 > Hi Mauro,
 >
 > I attached a screenshot of the result:
 >
 > 1. with the current version of `widget-specify-button' which clearly 
shows
 >    the unexpected appearance of the "OK" button when the button face 
has a
 >    :box attribute and the button prefix use a display space property.
 >
 > 2. with the patched version of `widget-specify-button' which shows the
 >    expected appearance of the same "OK" button.
 >

Thanks, I see it now.

 > It seems the problem is due to the invisible space inserted in front 
of the
 > button without specifying the face property, which causes a discontinuous
 > display of the button prefix when it uses a display space property.
 >

Agreed.

 > My proposed change just set the face of the invisible space to the button
 > face, which seems to fix the appearance of the button when the button
 > prefix has a display space text property.

I think it makes sense.  It's the only place in wid-edit that we add
something "extra" to the overlay (as in not specified in the :format
property) that represents the widget in-buffer, and we should respect
the button face.

 > I hope you will enjoy the new year.
 >
 > Thank you for your help.

Thanks, have a great year you too.