[gtk/wip/sort-icons-by-size] window: sort icons before adding to _NET_WM_ICON

[Ray Strode <halfline src gnome org>]

commit 6fcdcad853c0618214289211dc3060d319ed5752
Author: Ray Strode <rstrode redhat com>
Date:   Thu Aug 1 16:28:00 2019 -0400

    window: sort icons before adding to _NET_WM_ICON
    
    When processing the list of icons for a window to add them to
    _NET_WM_ICON gdk_x11_surface_set_icon_list only adds as many
    icon sizes as will fit within X protocol limits.
    
    It achieves this by keeping a running total of the number of
    bytes taken up by icons already processed and bails as soon
    as it goes over the limit.
    
    The problem is, one 512x512 icon is already over the limit,
    and so no icons will get added at all if the first icon in
    list is 512x512.
    
    Indeed, the code seems to assume the list is sorted from smallest
    icon to biggest icon.
    
    This commit changes the caller to sort the list.

 gtk/gtkwindow.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 1ee033f193..0adb757233 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -4007,6 +4007,18 @@ ensure_icon_info (GtkWindow *window)
   return info;
 }
 
+static int
+icon_size_compare (GdkTexture *a,
+                   GdkTexture *b)
+{
+  int area_a, area_b;
+
+  area_a = gdk_texture_get_width (a) * gdk_texture_get_height (a);
+  area_b = gdk_texture_get_width (b) * gdk_texture_get_height (b);
+
+  return area_a - area_b;
+}
+
 static GList *
 icon_list_from_theme (GtkWindow   *window,
                      const gchar *name)
@@ -4044,7 +4056,7 @@ icon_list_from_theme (GtkWindow   *window,
                                                     0);
       if (info)
         {
-         list = g_list_append (list, gtk_icon_info_load_texture (info));
+          list = g_list_insert_sorted (list, gtk_icon_info_load_texture (info), (GCompareDataFunc) 
icon_size_compare);
           g_object_unref (info);
         }
     }