I'm able to reproduce this with the mode-line as well, so it appears that
there may be a bug there too in the code that was copied to implement the
active/inactive faces in the header line. It's entirely possible that
there's a bug in nano-modeline, but it seems suspect that code was added to
consider windows and now this issue triggers when new windows are created
(and possibly when selection changes, I haven't eliminated whether or not
that's a factor yet).


Aaron


On Tue, Dec 03, 2024 at 9:06 PM, Aaron Jensen <aaronjensen@gmail.com> wrote:

> I bisected and found that this patch caused a regression in header-line
> formatting. I don't have the exact reproduction steps yet, but the gist is
> that I use a header-line with multiple faces in one window, then open a new
> popup window that has no header-line. The original window's header-line
> will get its faces changed slightly, but it's hard to tell how.
>
> Here's a video demonstrating it: https://share.cleanshot.com/CD9PtVv3
>
> You can see that the padding on the left of the header line goes away and
> the line numbers change to a variable pitch font. If I adjust my font size,
> the header line redraws with the proper faces. This will happen randomly,
> but I can force it with the font size change reliably.
>
> I'll see if I can narrow reproduction steps, but it may be worth
> considering a revert for now.
>
> Thanks,
>
>
> Aaron
>