Adwaita: Hide SSD box-shadow border on maximized windows

The 1px shadow was showing up on adjacent monitors when a SSD window was
maximized. Additionally this was causing mutter to skip direct scanout
of these windows, because they extend beyond the screen.

Related: https://gitlab.gnome.org/GNOME/mutter/-/issues/2304

diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 198690e5fbd06f0fbea7f70d8bda837a2c4a29c3..dc02b49acaeefdfc2f78480a9cab25fb7a4b98b5 100644 (file)
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -4601,6 +4601,8 @@ decoration {
   // just doing borders, wm draws actual shadows
   .ssd & { box-shadow: 0 0 0 1px $_wm_border; }
   .ssd &:backdrop { box-shadow: 0 0 0 1px $_wm_border_backdrop; }
+  .ssd.maximized &,
+  .ssd.maximized &:backdrop { box-shadow: none; }
 
   .csd.popup & {
     border-radius: $menu_radius;