[gtk/gtk-2-24: 1/2] Fix incorrect optimization in find_builtin_icon().

[Benjamin Otte <otte src gnome org>]

commit 9ce6f8086e3b264f30add5bd5bfab005c359ac66
Author: John Lindgren <john jlindgren net>
Date:   Sat Feb 17 22:03:27 2018 -0500

    Fix incorrect optimization in find_builtin_icon().
    
    When we found an icon with exactly the requested size, we'd stop
    searching immediately (good), but we'd neglect to set the returned
    min_difference to 0 (bad).  This caused theme_lookup_icon() to
    prefer other, potentially much worse, matches over the exact one.
    
    Cherry-picked from 5aa939dc (gtk-3-22)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=792738

 gtk/gtkicontheme.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index 532d94bee5..470158ceea 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -3396,6 +3396,7 @@ find_builtin_icon (const gchar *icon_name,
       
       if (difference == 0)
        {
+         min_difference = 0;
          min_icon = default_icon;
          break;
        }