[gtk+] scrolledwindow: handle NULL cursor safely

[Christian Hergert <chergert src gnome org>]

commit 73d09c8f7449e505bcfc5a6394702183319a2637
Author: Christian Hergert <chergert redhat com>
Date:   Wed Sep 28 12:37:41 2016 -0700

    scrolledwindow: handle NULL cursor safely
    
    It's possible to get a NULL cursor back if there are improperly
    configured or missing cursors on the system.

 gtk/gtkscrolledwindow.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index c4bec8b..27d5e7b 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -3396,7 +3396,7 @@ install_scroll_cursor (GtkScrolledWindow *scrolled_window,
   display = gdk_window_get_display (priv->scroll_window);
   cursor = gdk_cursor_new_from_name (display, "all-scroll");
   gdk_window_set_cursor (priv->scroll_window, cursor);
-  g_object_unref (cursor);
+  g_clear_object (&cursor);
 }
 
 static void