bug#46487: 27.1; Bubble effect when using :overline

[Eli Zaretskii]

> From: Clemens <clemera@posteo.net>
> Date: Sat, 13 Feb 2021 13:13:03 +0100
> 
> I'm trying to customize hl-line appearance, using the following face 
> definition:
> 
> (defface hl-line
>    '((t :overline "gray60" :underline "gray60" :background "gray" 
> :extend t))
>    "Default face for highlighting the current line in Hl-Line mode.")
> 
> 
> The problem is when navigating through lines this will create a bubble 
> effect. It doesn't happen when using only `:underline` and I wonder if 
> this could be avoided for `:overline`?

Set the value of overline-margin to zero, and Bob's your uncle (if you
don't mind the possibly adverse effects of that).