From 4456b068535c98c9edda7ce218787d2409f67697 Mon Sep 17 00:00:00 2001
From: Benjamin Otte <otte@redhat.com>
Date: Fri, 13 Jul 2018 14:52:43 +0200
Subject: [PATCH] window: Update opaque region if background-color changes

The opaque region is only set when the background color is opaque. So
we need to do something about it when the background color changes.

However, in the case where a size allocation is going to happen, we
already do this update in size_allocate(), so in that case avoid doing
it twice.
---
 gtk/gtkwindow.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 012f4efa58..9f495c12ab 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -6735,7 +6735,7 @@ subtract_corners_from_region (cairo_region_t        *region,
 
 static void
 update_opaque_region (GtkWindow           *window,
-                      GtkBorder           *border,
+                      const GtkBorder     *border,
                       const GtkAllocation *allocation)
 {
   GtkWidget *widget = GTK_WIDGET (window);
@@ -7825,11 +7825,24 @@ static void
 gtk_window_style_updated (GtkWidget *widget)
 {
   GtkCssStyleChange *change = gtk_style_context_get_change (gtk_widget_get_style_context (widget));
+  GtkWindow *window = GTK_WINDOW (widget);
 
   GTK_WIDGET_CLASS (gtk_window_parent_class)->style_updated (widget);
 
+  if (!_gtk_widget_get_alloc_needed (widget) &&
+      (change == NULL || gtk_css_style_change_changes_property (change, GTK_CSS_PROPERTY_BACKGROUND_COLOR)))
+    {
+      GtkAllocation allocation;
+      GtkBorder window_border;
+
+      _gtk_widget_get_allocation (widget, &allocation);
+      get_shadow_width (window, &window_border);
+
+      update_opaque_region (window, &window_border, &allocation);
+    }
+
   if (change == NULL || gtk_css_style_change_changes_property (change, GTK_CSS_PROPERTY_ICON_THEME))
-    update_themed_icon (GTK_WINDOW (widget));
+    update_themed_icon (window);
 }
 
 /**