[gtk/gtk-3-24: 1/2] Adwaita: Hide SSD box-shadow border on maximized windows

[Matthias Clasen <matthiasc src gnome org>]

commit 4873f63c07e62bd727746aa2d52cf1c13af6c9fd
Author: Sebastian Keller <skeller gnome org>
Date:   Sun Jun 19 16:24:59 2022 +0200

    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

 gtk/theme/Adwaita/_common.scss | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 198690e5fb..dc02b49aca 100644
--- 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;