[gtk/wip/exalm/revert-decoration] Adwaita: Revert black decoration background

[Alexander Mikhaylenko <alexm src gnome org>]

commit 60f69462fc46d871367d08c5d9384ef455293d1c
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sat May 30 15:22:40 2020 +0500

    Adwaita: Revert black decoration background
    
    Before I tried this change, I thought it might break apps that do
    transparent window background. So I checked a few that did this:
    gnome-terminal, tilix, kgx. It worked, so it must work everywhere, right?
    
    However, it just so happens that vte is drawn using CAIRO_OPERATOR_SOURCE
    operator rather than CAIRO_OPERATOR_OVER like everything else. This means
    that if vte widget is transparent, anything below it, like a black
    decoration background, won't be shown.
    
    So really it is still broken, so reverting it.

 gtk/theme/Adwaita/_common.scss           | 2 --
 gtk/theme/Adwaita/gtk-contained-dark.css | 6 +++---
 gtk/theme/Adwaita/gtk-contained.css      | 6 +++---
 3 files changed, 6 insertions(+), 8 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 2526ccbe84..da63d77dc9 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -4574,8 +4574,6 @@ decoration {
 
   .popup & { box-shadow: none; }
 
-  .csd & { background-color: black; } // transparent makes gtk3 leak light on the corners #2537
-
   // server-side decorations as used by mutter
   .ssd & { box-shadow: 0 0 0 1px $_wm_border; } //just doing borders, wm draws actual shadows
 
diff --git a/gtk/theme/Adwaita/gtk-contained-dark.css b/gtk/theme/Adwaita/gtk-contained-dark.css
index e5cd294a33..bff5a17a50 100644
--- a/gtk/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/theme/Adwaita/gtk-contained-dark.css
@@ -1826,15 +1826,15 @@ colorchooser .popover.osd { border-radius: 5px; }
 .scale-popup button:hover { background-color: rgba(238, 238, 236, 0.1); border-radius: 5px; }
 
 /********************** Window Decorations * */
-decoration { border-radius: 8px 8px 0 0; border-width: 0px; background-color: black; /* transparent makes 
gtk3 leak light on the corners #2537 */ box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(27, 27, 
27, 0.9); margin: 10px; }
+decoration { border-radius: 8px 8px 0 0; border-width: 0px; box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5), 0 
0 0 1px rgba(27, 27, 27, 0.9); margin: 10px; }
 
 decoration:backdrop { box-shadow: 0 3px 9px 1px transparent, 0 2px 6px 2px rgba(0, 0, 0, 0.2), 0 0 0 1px 
rgba(27, 27, 27, 0.9); transition: 200ms ease-out; }
 
 .maximized decoration, .fullscreen decoration, .tiled decoration, .tiled-top decoration, .tiled-right 
decoration, .tiled-bottom decoration, .tiled-left decoration { border-radius: 0; }
 
-.popup decoration { box-shadow: none; background: none; }
+.popup decoration { box-shadow: none; }
 
-.ssd decoration { background: none; box-shadow: 0 0 0 1px rgba(27, 27, 27, 0.9); }
+.ssd decoration { box-shadow: 0 0 0 1px rgba(27, 27, 27, 0.9); }
 
 .csd.popup decoration { border-radius: 5px; box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(27, 27, 
27, 0.8); }
 
diff --git a/gtk/theme/Adwaita/gtk-contained.css b/gtk/theme/Adwaita/gtk-contained.css
index 591ffb6255..5ac96ea0c2 100644
--- a/gtk/theme/Adwaita/gtk-contained.css
+++ b/gtk/theme/Adwaita/gtk-contained.css
@@ -1842,15 +1842,15 @@ colorchooser .popover.osd { border-radius: 5px; }
 .scale-popup button:hover { background-color: rgba(46, 52, 54, 0.1); border-radius: 5px; }
 
 /********************** Window Decorations * */
-decoration { border-radius: 8px 8px 0 0; border-width: 0px; background-color: black; /* transparent makes 
gtk3 leak light on the corners #2537 */ box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(0, 0, 0, 
0.23); margin: 10px; }
+decoration { border-radius: 8px 8px 0 0; border-width: 0px; box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5), 0 
0 0 1px rgba(0, 0, 0, 0.23); margin: 10px; }
 
 decoration:backdrop { box-shadow: 0 3px 9px 1px transparent, 0 2px 6px 2px rgba(0, 0, 0, 0.2), 0 0 0 1px 
rgba(0, 0, 0, 0.18); transition: 200ms ease-out; }
 
 .maximized decoration, .fullscreen decoration, .tiled decoration, .tiled-top decoration, .tiled-right 
decoration, .tiled-bottom decoration, .tiled-left decoration { border-radius: 0; }
 
-.popup decoration { box-shadow: none; background: none; }
+.popup decoration { box-shadow: none; }
 
-.ssd decoration { background: none; box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.23); }
+.ssd decoration { box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.23); }
 
 .csd.popup decoration { border-radius: 5px; box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(0, 0, 
0, 0.13); }