[gtk+/gtk-3-8] gdkdisplay-x11: Do not pass a NULL source device to _gdk_display_device_grab_update

[Matthias Clasen <matthiasc src gnome org>]

commit 41ba15bbf26e3dbfa03d0b7d2df7a6c65a2524fc
Author: Carlos Garcia Campos <cgarcia igalia com>
Date:   Tue Jun 18 13:20:10 2013 +0200

    gdkdisplay-x11: Do not pass a NULL source device to _gdk_display_device_grab_update
    
    Pass the master device instead if the last slave is NULL. This is
    unlikely to happen in most of the cases, but can happen when running
    unit tests where there's no pointer interaction to update the last
    slave.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696756

 gdk/x11/gdkdisplay-x11.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gdk/x11/gdkdisplay-x11.c b/gdk/x11/gdkdisplay-x11.c
index 93a472c..2791d8f 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -1741,7 +1741,8 @@ device_grab_update_callback (GdkDisplay *display,
 
   pointer_info = _gdk_display_get_pointer_info (display, device);
   _gdk_display_device_grab_update (display, device,
-                                   pointer_info->last_slave, serial);
+                                   pointer_info->last_slave ? pointer_info->last_slave : device,
+                                   serial);
 }
 
 #define XSERVER_TIME_IS_LATER(time1, time2)                        \