macosx: added an extra sanity check to fix video playback on Macs using the...

macosx: added an extra sanity check to fix video playback on Macs using the QT4 interface (fullscreen mode still broken)

modules/gui/macosx/vout.m

 /*****************************************************************************
  * vout.m: MacOS X video output module
  *****************************************************************************
- * Copyright (C) 2001-2007 the VideoLAN team
+ * Copyright (C) 2001-2008 the VideoLAN team
  * $Id$
  *
  * Authors: Colin Delacroix <colin@zoy.org>
@@ -441,6 +441,9 @@ int DeviceCallback( vlc_object_t *p_this, const char *psz_variable,
 - (void)manage
 {
     /* Disable Screensaver, when we're playing something, but allow it on pause */
+    if( !VLCIntf || !VLCIntf->p_sys || !VLCIntf->p_sys->i_play_status )
+        return;
+
     if( VLCIntf->p_sys->i_play_status == PLAYING_S )
         UpdateSystemActivity( UsrActivity );
 }