[gtk] Adwaita: menu border-radius fix from gtk3

[Jakub Steiner <jimmac src gnome org>]

commit a3e517aa9cd61e71041488a3b042f9ad3fc1a961
Author: Jakub Steiner <jimmac gmail com>
Date:   Wed Feb 6 14:34:55 2019 +0100

    Adwaita: menu border-radius fix from gtk3
    
    - avoid painting over the rounded corners with background

 gtk/theme/Adwaita/_common.scss           | 4 ++++
 gtk/theme/Adwaita/gtk-contained-dark.css | 2 ++
 gtk/theme/Adwaita/gtk-contained.css      | 2 ++
 3 files changed, 8 insertions(+)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index ffcc60a75a..34a34b42b4 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -2066,6 +2066,10 @@ menubar,
   .csd.popup decoration {border-radius:0;}
 }
 
+// Needed to make the border-radius of menus work
+// otherwise the background bleeds out of the menu edges
+.background.popup { background-color: transparent; }
+
 menu,
 .menu,
 .context-menu {
diff --git a/gtk/theme/Adwaita/gtk-contained-dark.css b/gtk/theme/Adwaita/gtk-contained-dark.css
index cc7c39779b..32bd158a52 100644
--- a/gtk/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/theme/Adwaita/gtk-contained-dark.css
@@ -815,6 +815,8 @@ menubar > menuitem:disabled, .menubar > menuitem:disabled { color: #919190; box-
 
 menubar .csd.popup decoration, .menubar .csd.popup decoration { border-radius: 0; }
 
+.background.popup { background-color: transparent; }
+
 menu, .menu, .context-menu { padding: 4px 0px; background-color: #2f2f2f; border: 1px solid #1b1b1b; 
border-radius: 5px; }
 
 .csd menu, .csd .menu, .csd .context-menu { border: none; }
diff --git a/gtk/theme/Adwaita/gtk-contained.css b/gtk/theme/Adwaita/gtk-contained.css
index 099d6cf024..2c5bb029fc 100644
--- a/gtk/theme/Adwaita/gtk-contained.css
+++ b/gtk/theme/Adwaita/gtk-contained.css
@@ -823,6 +823,8 @@ menubar > menuitem:disabled, .menubar > menuitem:disabled { color: #929595; box-
 
 menubar .csd.popup decoration, .menubar .csd.popup decoration { border-radius: 0; }
 
+.background.popup { background-color: transparent; }
+
 menu, .menu, .context-menu { padding: 4px 0px; background-color: #ffffff; border: 1px solid #cdc7c2; 
border-radius: 5px; }
 
 .csd menu, .csd .menu, .csd .context-menu { border: none; }