[gtk/toolbar-combobox: 2/3] Don't make all buttons in toolbars flat

[Matthias Clasen <matthiasc src gnome org>]

commit 860821114a6fdf8076872a601a07209321016f08
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Oct 28 21:05:13 2021 -0400

    Don't make all buttons in toolbars flat
    
    When a combobox is put in a toolbar, we don't want
    its button to lose its border.
    
    Fixes: #4384

 gtk/theme/Default/_common.scss | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
---
diff --git a/gtk/theme/Default/_common.scss b/gtk/theme/Default/_common.scss
index ebef2a800c..80d7a061c3 100644
--- a/gtk/theme/Default/_common.scss
+++ b/gtk/theme/Default/_common.scss
@@ -606,7 +606,7 @@ button {
     min-width: 26px;
     min-height: 32px;
 
-    &.image-button { 
+    &.image-button {
       min-width: 30px;
       &:only-child {
         margin: 4px;
@@ -895,7 +895,15 @@ modelbutton.flat arrow {
 
 /* oldstyle toolbar buttons */
 
-.toolbar button {
+.toolbar > button,
+.toolbar > :not(.linked) > button,
+.toolbar :not(.linked) > menubutton > button,
+.toolbar :not(.linked) > scalebutton > button,
+.toolbar :not(.linked) > dropdown > button,
+.toolbar :not(.linked) > colorbutton > button,
+.toolbar :not(.linked) > fontbutton > button,
+.toolbar :not(.linked) > appchooserbutton > button,
+.toolbar :not(.linked) > combobox > box > button {
   margin: 1px;
 
    @extend %button_basic_flat;
@@ -2401,7 +2409,7 @@ switch {
     border-radius: 50%;
     transition: $button_transition;
   }
-  
+
   > image { color: transparent; } /* only show i / o for the accessible theme */
 
   &:hover > slider {
@@ -2510,7 +2518,7 @@ radio {
       }
     }
   }
-  
+
   @if $variant == 'light' {
     // the borders of the light variant versions of checks and radios are too similar in luminosity to the 
selected background
     // color, hence we need special casing.