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

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 9dbc19ea174d880d5149945d832f0bcf08bfa406
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 e1a28ea..347bcce 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -1737,7 +1737,8 @@ 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)                        \