[clutter] input: Add a check on the argument

[Emmanuele Bassi <ebassi src gnome org>]

commit 251d3b545e4df6c55dd596424dda3470564f16cf
Author: Emmanuele Bassi <ebassi linux intel com>
Date:   Thu Mar 1 15:11:59 2012 +0000

    input: Add a check on the argument

 clutter/clutter-input-device.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/clutter/clutter-input-device.c b/clutter/clutter-input-device.c
index efec797..41196ee 100644
--- a/clutter/clutter-input-device.c
+++ b/clutter/clutter-input-device.c
@@ -1421,9 +1421,10 @@ _clutter_input_device_select_stage_events (ClutterInputDevice *device,
  * equivalent evdev keycode. Note that depending on the input backend
  * used by Clutter this function can fail if there is no obvious
  * mapping between the key codes. The hardware keycode can be taken
- * from the hardware_keycode member of #ClutterKeyEvent.
+ * from the #ClutterKeyEvent.hardware_keycode member of #ClutterKeyEvent.
  *
  * Return value: %TRUE if the conversion succeeded, %FALSE otherwise.
+ *
  * Since: 1.10
  */
 gboolean
@@ -1433,6 +1434,8 @@ clutter_input_device_keycode_to_evdev (ClutterInputDevice *device,
 {
   ClutterInputDeviceClass *device_class;
 
+  g_return_val_if_fail (CLUTTER_IS_INPUT_DEVICE (device), FALSE);
+
   device_class = CLUTTER_INPUT_DEVICE_GET_CLASS (device);
   if (device_class->keycode_to_evdev == NULL)
     return FALSE;