[goffice] Canvas: avoid win32 problem with compositing.

[Morten Welinder <mortenw src gnome org>]

commit 80db89a14a9d7bbab6d92c0e3419aad85b7cbbfd
Author: Morten Welinder <terra gnome org>
Date:   Tue Jan 6 15:12:23 2015 -0500

    Canvas: avoid win32 problem with compositing.

 ChangeLog                   |    5 +++++
 goffice/canvas/goc-widget.c |    3 ++-
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 8713e15..f2c4399 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-06  Morten Welinder  <terra gnome org>
+
+       * goffice/canvas/goc-widget.c (goc_offscreen_box_realize): Only
+       make window composited if the screen is.  See bug 741455.
+
 2015-01-04  Morten Welinder  <terra gnome org>
 
        * goffice/gtk/goffice-gtk.c (update_preview_cb): Fix flags
diff --git a/goffice/canvas/goc-widget.c b/goffice/canvas/goc-widget.c
index ff6ca75..835c1a5 100644
--- a/goffice/canvas/goc-widget.c
+++ b/goffice/canvas/goc-widget.c
@@ -217,7 +217,8 @@ goc_offscreen_box_realize (GtkWidget *widget)
        window = gdk_window_new (gtk_widget_get_parent_window (widget),
                                 &attributes, attributes_mask);
        gtk_widget_set_window (widget, window);
-       gdk_window_set_composited (window, TRUE);
+       if (gdk_screen_is_composited (gdk_window_get_screen (window))) 
+               gdk_window_set_composited (window, TRUE);
        gdk_window_set_user_data (window, widget);
 
        g_signal_connect (window, "pick-embedded-child",