Subject: Re: bug#28033: [PATCH] Add new face 'header-line-highlight'

From: Alex <[email-masked]>
Date: Wed, 09 Aug 2017 23:36:19 -0600

Eli Zaretskii <[email-masked]> writes:

>> From: Alex <[email-masked]>
>> Date: Wed, 09 Aug 2017 17:29:19 -0600
>> 
>> Some header-line configurations don't interact nicely with the
>> 'highlight' face, particularly when they use the :box attribute.
>
> Can you elaborate about the problem and why introducing a new face is
> the solution for it?
>
> Thanks.

The problem is that the highlight face, which is used for highlighting
links and other mouse-sensitive buffer text frequently, may not always
look nice with the header-line face. I've attached a picture
demonstrating one possible issue. In it, the header-line face has a :box
attribute with line-width 4, but the highlight face does not. This
results in the characters at the ends being clipped.

A new face allows for users to customize it to match the customization
of the header-line face while not affecting all other uses of the
highlight face.

I believe the use case of this face is very similar to
'mode-line-highlight', which was added quite a while ago.