[gnome-photos] Fix crash when trying to use window after it has been destroyed

[Debarshi Ray <debarshir src gnome org>]

commit e173959404af3f95d3fd4e116f765931d10268a0
Author: Debarshi Ray <debarshir gnome org>
Date:   Mon Feb 23 16:36:43 2015 +0100

    Fix crash when trying to use window after it has been destroyed
    
    Ideally we should cancel all pending operations when the main window
    has been destroyed, but that will require a more intrusive change.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=738527

 src/photos-base-item.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/src/photos-base-item.c b/src/photos-base-item.c
index e301e20..3b5a4eb 100644
--- a/src/photos-base-item.c
+++ b/src/photos-base-item.c
@@ -1,7 +1,7 @@
 /*
  * Photos - access, organize and share your photos on GNOME
  * Copyright © 2014, 2015 Pranav Kant
- * Copyright © 2012, 2013, 2014 Red Hat, Inc.
+ * Copyright © 2012, 2013, 2014, 2015 Red Hat, Inc.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -208,7 +208,7 @@ photos_base_item_check_effects_and_update_info (PhotosBaseItem *self)
   GList *windows;
   GdkPixbuf *emblemed_pixbuf = NULL;
   GdkPixbuf *thumbnailed_pixbuf = NULL;
-  GdkWindow *window;
+  GdkWindow *window = NULL;
   gint scale;
 
   if (priv->original_icon == NULL)
@@ -294,7 +294,9 @@ photos_base_item_check_effects_and_update_info (PhotosBaseItem *self)
   app = g_application_get_default ();
   scale = photos_application_get_scale_factor (PHOTOS_APPLICATION (app));
   windows = gtk_application_get_windows (GTK_APPLICATION (app));
-  window = gtk_widget_get_window (GTK_WIDGET (windows->data));
+  if (windows != NULL)
+    window = gtk_widget_get_window (GTK_WIDGET (windows->data));
+
   priv->surface = gdk_cairo_surface_create_from_pixbuf (thumbnailed_pixbuf, scale, window);
 
   g_signal_emit (self, signals[INFO_UPDATED], 0);