Window margins cause titlebar issues in Mutter 44

[davidmhewitt]

In Mutter 44, X11 SSD titlebars run as a separate GTK 4 process. With our stylesheet, they look like this:

This is due to this margin in the stylesheet:

stylesheet/src/gtk-4.0/widgets/_windows.scss

Line 8 in 0c84118

margin: rem(12px);

If we remove this margin, it looks like this:

Can we have a bit of an investigation into why we have a margin here when Adwaita doesn't, and whether it's needed with a view to removing it in the next release?

[alice-mkh]

That margin looks like it’s a gtk3-ism, since iirc 3 was using it to determine the invisible border size, while 4 doesn’t. You also want to disable round corners for ssd windows, you can see the bottom corners are glitchy on that terminal.

[danirabbit]

Yup that's exactly it. It was a quirk to set the resize area. I'll do a branch :)