dbus: Fix GetAspectRatio() crash and add note for SetVideoPosition().

modules/control/dbus.c

@@ -1312,8 +1312,10 @@ DBUS_METHOD( SetVideoPosition )
         p_vout = input_GetVout( p_input );
         if( p_vout )
         {
-            int i_ret;
-
+            int i_ret = 0;
+            /* NOTE: this doesn't work when the video output is embedded
+             * in the main window. Use: vlc --no-embedded
+             */
             var_SetInteger( p_vout, "video-x", i_x );
             var_SetInteger( p_vout, "video-y", i_y );
             i_ret = vout_Control( p_vout, VOUT_SET_POSITION, i_x, i_y);
@@ -1360,6 +1362,9 @@ DBUS_METHOD( GetAspectRatio )
     }
     pl_Release( (vlc_object_t*) p_this );
 
+    if( !psz_aspect )
+        psz_aspect = strdup( "default" );
+
     ADD_STRING( &psz_aspect );
     free( psz_aspect );