[gtk/matthiasc/for-master] Adwaita: Don't do n-th child things for list rows

[Matthias Clasen <matthiasc src gnome org>]

commit 3d3fa232f71468a9e0e9876933d821ea5ac74ece
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 11 13:07:31 2020 -0500

    Adwaita: Don't do n-th child things for list rows
    
    Making the list row child css depend on the position
    is very expensive, and does not acutally work correctly
    (since we don't have widgets for all children, so the
    position of the child widget does not reflect the actual
    model item position).

 gtk/theme/Adwaita/_common.scss | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index a552965cdd..e7eb52228d 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -3098,12 +3098,12 @@ list {
   > row.expander { padding: 0px; }
   > row.expander .row-header { padding: 2px; }
 
-  &.horizontal row.separator:not(:first-child),
-  &.separators.horizontal > row:not(:first-child) {
+  &.horizontal row.separator
+  &.separators.horizontal > row {
     border-left: 1px solid $_treeview_borders_color;
   }
-  &:not(.horizontal) row.separator:not(:first-child),
-  &.separators:not(.horizontal) > row:not(:first-child) {
+  &:not(.horizontal) row.separator
+  &.separators:not(.horizontal) > row {
     border-top: 1px solid $_treeview_borders_color;
   }
 }