Qt4: passing pointers over thread signals is not allowed...

...unless proper reference counting si involved,
or the signal is blocking queued (but that is deadlock-prone).

Ref: LP#528285

modules/gui/qt4/components/info_panels.cpp

@@ -162,6 +162,8 @@ MetaPanel::MetaPanel( QWidget *parent,
  **/
 void MetaPanel::update( input_item_t *p_item )
 {
+#warning This is wrong.
+#if 0
     if( !p_item )
     {
         clear();
@@ -243,7 +245,7 @@ void MetaPanel::update( input_item_t *p_item )
     }
 
     art_cover->showArtUpdate( file );
-
+#endif
 }
 
 /**